Possible alignments at Mycenae, Greece
The are nine tholoi around Mycenae/Mikines
Peloponnese, Greece), but two are from the last (same) building period
(1300 - 1200 BCE): Treasury of Atreus (also
Treasure of Atreus, Tomb of Agamemnon or T3) and Tholos
of Clytemnestra (T6). These two may have possible alignments (see
to my work by Schaefer , page
The following stomion (passage) directions were measured (using compass
in March 2004):
Beside possible alignments also sound
(reverberation time: RT60) were done at the Treasury of
Atreus (T3), T6, T11, T13, T14 and T15.
The below ideas are the result of the folowing visits: April
1998, March 1999, March 2004, April
2007, April 2008, and Sept.
Possible equinox alignment at Treasury of
The longitude and latitude of the Treasury of Atreus is: 22°
45' east and 37° 44' north both +/- 1'. It is build around 1250
The horizon around the Treasury of Atreus
The horizon, formed by Mount Zara, seen from just in the covered
passage (stomion) can be seen
A panorama picture made at the beginning of the dromos of this tholos,
can be viewed as a normal
You can see the following below:
- location of sunrise at summer solstice
location of sunrise at spring equinox
The above sun (March 31st, 06:26 UTC = 09:26 local time) is
almost at the same
azimuth as sunrise on equinox.
Sun inside Treasury of Atreus.
The reason why the sun will be on the inside chamber wall, is explained
with the following picture:
The picture let you see a compilation of three things:
As you see, the sky can be seen just at the back wall at eye height
is bright sky light to be seen). The altitude from eye height near the
back wall along the base of the triangular structure towards the
outside its top, is
around 22°.8 +/- 1° (measured using clinometer):
- the wall + triangular structure (in literature called
relieving triangle, but I doubt the correctness of
this term) is a picture made at eye
from near the back wall towards the outside
View of triangular structure from outside
Remember that the top layers of the
triangular structure have moved
somewhat (see above picture), so that the highest part of the top is
Close-up view of triangular structure from inside
- the two column wise inset is a picture made from the horizon just
mid way the doorway passage
- the blue line is the horizon (due to the hill opposite Treasury
Treusury of Atreus (Wace , plate 5)
The maximum altitude that the sun light is still to be seen on the
is presently at 23° 45' +/- 5'.
The direction of the dromos is:
So with all this information, it can be deducted
(using e.g. SkyMap) that
the sun will shine two periods inside the chamber:
- some 100° 45' +/- 1°
from a map of the Mycenaean environment
- some 105° 6'
from Wace , plate 56. I assume this
is excluding correction for magnetic north, so if I include
this (3° 24'), the direction becomes 101° 42'
- around 102° 5' +/- 15'
compass reading, including
the correction for magnetic north
- 101° 13' +/- 5'
using the sun light as a theodolite inside the chamber
- sunrises around spring equinox (March 21st)
Precise dates and times not yet known, but it will be in the range
and 06:45 UTC (remember local time is UTC+2 or UTC+3 [incase of
Furthermore the sun light
to be in the chamber (at present times) for something like a month.
around autumn equinox (Sept. 23rd)
Precise dates and times not yet known, but it will be in the range
and 06:30 UTC (remember local time is UTC+2 or UTC+3 [incase of
Modeling of the Treasury of Atreus
A 3D world around Treasury of Atreus has been
made (the actual top of the hill opposite Treasury of Atreus is not
yet visible in the world, I am working on this though).
An animation of the sun path on the back wall can be seen below:
Sunrise on June 20th,
With the help of Vassilis Merekoulias and Panagiotis Christias we
proofed that the sun could not enter into the chamber on the longest
The archeological office in Nafplion gratefully provided the permission
to observe this from 06:30 local time. This experience let to the idea
that the sun would get into the building around the equinoxes.
Sunrise on March 31st,
On March 31st, 1999 video was made of the
on the chamber wall.
- A composite picture of the chamber wall has been made on two
and 09:18 local time [UTC+3]) when the sun was not behind the
You can clearly see the triangular shape of the sun patches, due to the
video of the last moments (around 09:23 local time [UTC+3]) the sun
on the chamber wall.
It starts with no sun (due to clouds) and then the last minute of sun
light on the wall of the chamber can be seen. It did not stop
to a cloud, because the sun was still shining outside (not for long
Sunrise on Sept. 20th, 2002
On this day George Chronis, security office of Mycenae made
pictures of the sun on the back wall, which is indeed within the
Sunrises in March, 2004
To find out the first date the sun shines on the wall in March 2004, a
was planned from March 10 until 17th 2004 to be sure the first light
inside the chamber was in the middle of the trip. The following results
- On March 11th, 2004 the sun was not obstructed by clouds, but was
not within the chamber
- On March 12th, 2004 no sun due to clouds
- On March 13th, 2004 no sun due to clouds
- On March 14th, 2004 the sun was not obstructed by clouds
looked like the sun wanted to peep in (around 8:33 [UTC+2]), but there
very faint light. But a shadow was casted during a few minutes. I think
was the sun's glare that gave this glare.
- On March 15th, 2004 the sun was inside the
chamber for 3 whole
minutes (8:32 to 8:35 local time [UTC+2]). A video has been made.
Sun on backwall at 8:33
- On March 16th, 2004 the sun was inside the chamber for some 5
(8:30 to 8:35 local time [UTC+2]). A video has been made
to see animation).
Sun on backwall at 8:33 [UTC+2]
Observations in September 2006 and March/April 2007
Shophia Terovola did observations of the sunlight in the chamber. I am
very grateful for her effort and she provided permission to put these
dates on this web page. Here are the dates:
That the sunlight was not seen before or after these dates could be due
to clouded weather, no observation done or no possibility to have sun
inside the chamber.
- first event seen on Sept. 2nd, 2006
- last event seen on Sept. 20th, 2006
- first even seen around March 27th, 2007 (not fully sure about
- last event seen around April 7th, 2007 (plus or minus one day)
The declinations of these dates are fitting with the declinations found
for the first day (March 15th, 2004) and the
calculated end date (April 12th, 2007).
Sunrises in April, 2007
To find out the last date the sun shines on the wall in April 2007, a
was planned from April 14 until 20th 2007 to try to catch the last
inside the chamber. The following results
The present opening of the triangular structure is
at its base some 17%
smaller then originally (due to this small stone on the right):
- April 15th, 2007; the sun was not obstructed by clouds and
not within the chamber:-( No sun glare was seen, so at least I was 2 or
more days too late.
On the right bottom side of the inside of the
structure a small part is blocked off by a small stone
(this small stone is not original, but was part of restorations done in
1950's (Pers. comm. Gregory Chronis ).
- April 16th, 2007; the sun most of the time (90%) obscured by
clouds. Some video have been taken from the outside towards the small
stone that blocks the sun light.
The sun peeped through the clouds and thus some sun light has been seen
on this small stone. If that small stone would not have been (like in
former times) there is a
large chance that the sunlight would have been projected on the chamber
- April 17th, 2007; 100% clouded
- April 18th, 2007; 0% clouds. Made some pictures from a hanging
camera in front of the triangular structure.
- April 19th, 2007; 0% clouds. Made sure that even the top of the
triangular structure can let the sun shine through.
- April 20th, 2007: high up clouds, so a milky sun. Got the sun
light through the doorway into the chamber and reiterated the sun
through the triangular structure, and indeed the sun light goes really
through the very top of the triangular structure.
This reduces the number of days the sun shines at present times inside
chamber from the
calculated(/original?) 34 days to 28 days (so untill around April
12th). Remember beside this modern obstruction, the outside of the
triangle has also changed (caved in/pushed up somewhat) and this would
considerably change the sky window of the
Sunrises in April, 2008
To really find out the last date the sun shines in present days on the
wall, again a
was planned now from April 8th until 14th 2008 to try to catch the last
inside the chamber. The following results
- April 8th, 2008.
No clouds. The Sun touched the outside of the top of triangular
structure at 05:26 [UTC]. Was not inside the chamber, because the site
until 05:30 [UTC]:-( Started video taping at 05:31 [UTC] until 06:12
- April 9th, 2008
Lots of clouds, at least 99%. The Sun casted a sunspot at 05:28 [UTC]
in the chamber.
Could have been somewhat earlier, because there were clouds and the
tholos was still closed off... Same for the moment of final sunlight,
it is not
precisely known, weak sunlight was present on the wall around 06:08
[UTC], but definitely not anymore at 06:10 [UTC].
- April 10th, 2008
Sun was visible all the time, but it was in a haze (very high up
clouds). The Sun touched the top of the triangular structure on the
outside wall before 05:27 [UTC]. The sun got into the chamber around
05:33 [UTC]. The Sun left the chamber for a few minutes around 05:42
[UTC], because the light path was obstructed by the modern repair.
After coming back, it left the chamber at 06:06 [UTC].
Not only the sunlight passes through the triangular structure, this owl
takes a nap in one of the other tholos tombs:
- April 11th, 2008
The Sun was visible all the time, but it was in a heavy haze. The sun
was not seen earlier then around
05:49 [UTC] in the chamber (so this 'is' the light as of yesterday 5:42
[UTC]; it might thus be that the sun now comes in much later due to
obstruction). The Sun light left the chamber at 06:03 [UTC]; did not
see explicit sun light, but an object (like hand) casted no shadow
anymore at that time.
- April 12th, 2008
The Sun was visible all the time, but it was in a heavy haze. The sun
was not seen earlier then around
05:52 [UTC] in the chamber. The Sun light left the chamber at 06:00
- April 13th, 2008
Clouded and a very heavy haze. No direct sunlight in the chamber at the
moments when there was some Sun. It is save to say that today no Sun
would have entered.
- April 14th, 2008
Sunrises in Sept, 2009
The aim of trip was to search for possible buildings on mount
Earth might have revealed something; but it could be wishful
thinking;-). But due to possible issues with snakes this has been
postponed (winter time would be better). So only sun spot observations:
- Sept. 17th, 2009
Hazy weather (24 C). Sun came inside the chamber around 05:54 [UTC]. It
left the chamber around 06:18 [UTC]. See for a video here.
- Sept 18th, 2009
Less hazy weather (cleared somewhat up due to the thunderstorm last
night, with several power outages). Sun inside the chamber around 05:
58 [UTC]. It left the chamber
around 6:19 [UTC]. See for a video here.
- Sept 19th, 2009
Less hazy weather (some high clouds and at the first few minutes also
some low clouds). Sun inside the chamber around 06: 01 [UTC]. It left
around 6:21 [UTC].
- Sept 20th, 2009
Still hazy weather (many high clouds and low clouds). Sun inside the
chamber for around 4 minutes due to clouds (~20% of time).
- Sept 21st, 2009
Cloudy. When clouds were gone, Sun was in chamber (at somewhat earlier
than 06:04 [UTC). So this was not the fist possible light in the
chamber (it was too strong). The sun was last seen around 06:20 [UTC].
It was already the camera obsura effect and close to full blocking.
(around 85% of Sun).
- Sept 22nd, 2009
High clouds, Sun came in chamber at 06:05 [UTC). The sun left around
- Sept 23rd, 2009
At the start a few light clouds, Sun came in chamber at 06:07 [UTC).
left around 06:18 [UTC].
Reconstruction of the sky window of
the triangular structure
still under construction!!!
The above observations of the sun spot on the back wall can be
in the below graph, where the start (light blue) and end (dark blue)
azimuth and apparent altitude of the Sun have been plotted. The yellow
the apparent altitude of the horizon (due to mountain Zara).
A computer model for the triangular structure and the tholos has
been made and the resulting sky window
the space within the pink-ish line-form and the yellow horizon curve.
might wonder why the computer model is so close to the observations?
This is because the input parameters of the computer model (height,
width and length of the triangular structure) have been changed in such
a way that it best maps the observations.
It is not that easy to measure in real live
the in/outside of the triangular structure (unintended protruding
stones due to small cave-in/push-up over time, difficult to reach,
precision needed, tourist/archaeological monument, etc.). This will
need permission from the owners of the monument (Hellenic
Minsitry of Culture
) as a good precise size
analysis will be needed. This permission will be seeked in the
coming time (say for a winter time project?).
Two aspects have changed the sky window of the triangular structure
If we assume that the above
changes can be compensated for, then the
sky window of former times will be larger. See below picture:
- the slight cave in/push-up of several of the top stone layers
slightly moved stones at the top of the triangle).
- the modern obstruction in the right lower corner (since the
So some (not all!) explanation to the above picture:
With the present data (still
investigating this though), we need an extra three days
after(/earlier) equinox to see an increased lowest location of the sun
- the red-ish line-form is the sky window of the triangular
structure when it was build (using data from Wace [1921-1923]). So nice and smooth on the
sides, and also
no unintended protruding stones inside. The last might not be
Still trying to make this more precise (might also need on site
investigations, as stated above).
- the pink-ish line-form is the sky window of the triangular
structure as witnessed today (deducted from the observed sun spots).
- both of the above sky windows are limited by the horizon's
- the thick blue line is a declination of 0 [deg]; using so present
equinox definition and independent of the epoch.
- the thin blue lines, right beside the thick blue line, are
declinations of 0.25 and -0.25 degree. A declination difference of
~0.25 degree happens between center of the Sun and the left (or right)
rim of the Sun or a appr. a
day earlier or later.
- there are some more light blue-ish lines for different
declinations (steps of 5 degrees; see legend).
As stated by Heilbron :
equinox alignments need to be build in sturdy and well settled
buildings; so if the Treasury
of Atreus was meant to be aligned with equinox, the relieving triangle
did not survive the test of time fully;-).
The triangular structure of the tholos of
Clytemnestra has stand much better the test of time (so they had
If planning your own observations
It is important to
write down if an observation was done and if the sun did not reach
wall due to clouds. A form and procedures is
Since when is the light in the chamber
There are a few accounts that it is known for quite some time:
It does not look like that it is known (widely) that this phenomena is
- A different light in Treasury of Atreus; the sun light through
the top hole. Drawing by E Dodwell, 1834 hanging in Mycenae Museum.
Note also a cave-in/push-up at the triangular structure.
- Another light into the tholos, by English Photo Co. in 1907
(picture hanging at Hotel La Belle Helene de Menelas; House of
Schliemann, Mycenae/Mikines: + 30 275 106225, e-mail: bellhel@+otenet.gr
[remove plus sign!]). This
light might have
been produced as follows: It was when the Sun was shining in
the direction of the dromos (no shadow on both dromos walls), but it
looks not to be through the triangular structure. It looks that part of
structure was still caved in/pushed up, as seen in the 1834 drawing.
- around 1950's the cave-in/push-up (which changed the
triangular structure slightly) has been repaired (by
Wace/Mylonas?). This would be the earliest date that light through the
tringular structure could be witnessed in its full glory.
- around 1960's someone (still living in 2004 in Mycenae) working
at the site, knew about the sun getting inside the building.
- around 1980's a party tried with mirrors and artificial light to
mimic the light path inside the chamber, to see what corners it could
- end April 1998 the first investigation of the light was
on the web by the author (Victor Reijs). A computer (VRML) model had
and first it was thought that the chamber would receive Sun light
around summer solstice (using a crude map of the region), but an actual
visit near summer solstice (June 1998)
it possible to deduct that the sun would get in around the equinoxes.
- first video taken of
the sun light in the chamber in March 1999 by the author (Victor Reijs).
- in Dec. 1999 an article was published in National Geographic with
picture of the light beam (Alexander ,
it is assumed to be taken in Sept. 1998.
- Informed John Lavery in August 2001 about my work and received
back a postcard in 2001, where he acknowledged he received my copies of
my web page. He made (date unknown) a personal note about light inside
Atreus (Atreus illuminated; pers. comm, Gregory Chronis ; Gregory
had a copy but was
not able to retrieve it), but I never saw the note (also due to John's
untimely death [200?]). If you have a copy of this note, please let me know.
- the book Mycenae; A guide to
its Ruins and its History (Mylonas )
has a picture of the sun light patch. Don't know yet
when the picture was taken (it was not in the earlier versions, like
1972, of his
- The sun light can at present be seen on the wall of
the equinoxes (spring and autumn)!
This is true if the triangular structure was open! But it seems though
that it could have been decoratively closed some
time(s) by a plaque. Furthermore triangular structures and light
(like Newgrange, Crantit
are always prone to be filled, so it is difficult to say more about
- I don't think the triangular structure
for relieving the load. The lintel above the passage is able to bear
load. It is some 120 cm thick and made of granite.
The above picture provides some insight for a structural engineering
The entrance (5,3 m high and 5,7 m in length) has a granite lintel of
m thickness (one single slab!). The weight on this lintel is on
the first 4,5 m around 100 kN/m2 and on the last 1,2 m
400 kN/m2 (this last weight is made up of some 7.5 m3
stones and some 7.5 m3 wet sand per meter wall).
A simpler (worst case) model deducted from the above: a 1 m wide
beam, fixed on both sides at 2.4 m apart, is bearing a weight of some
What is the safe thickness [H] of the beam
so that it does not collapses?
Thanks to Mr. Dave Karr a solution to this problem has been found.
The following information is used: Young's modulus of granite is
kN/m2 and its failure strain around 0.003. The max.
due to the 400 kN/m2 weight on the beam, is around M=100
The minimum save thickness of the beam is around:
H = SQRT(6 * M / failure
modulus) = SQRT (6 * 100 / 43800) = 0.12 [m]
This can also be calculate with a
structural beam design and stress analysis program (Beam 2D). This
program calculates an H of around 0.2 [m]
(due to the high stress/moment at the end points).
The following can now be deducted:
Thus the triangular structure and the thick lintel are not
from a structural engineering view point, but I could be wrong.
If you know some articles/simulations on this constructional design
other results, let me
- H (0.2 [m]) is considerably
then the thickness of the lintel (1.2 [m]) at Treasury of Atreus. So,
if the triangular structure was not present (and thus all
was on the lintel), the lintel would not break with the present
- Due to the presence of the triangular structure, the thickness
could be zero. Except for keeping the former entrance doors into place,
it needs some thickness.
- While visiting all the 9 tholos thombs around Mycenae in
2004, the number of broken lintel stones is around 5-6 of a total of
around 25 stones. Most of the lintel where fallen due to instable
support, so I think it is not possible to state that lintels were
broken due to pressure, but more due to breaking when falling down.
- It is very well possible that all tholos thombs had triangular
structures. Even the olds ones, because in 1997 this was at least found
in one (the tomb of Aegisthus) of the three oldest tholos thombs
- The story goes that the closed triangular structure was there to
keep the spirits close to the body (as long as it was not yet fully
decomposed). After decomposition it looks like Mycenean culture did not
regard bones as respectful (they were shoveled aside or thrown out of
the chamber) (Mylonas ,
- The National
Archaeological Museum in Athena (Mycenaean room, items: 1322, 1433,
1470 and 1479), Munich Museum, Mycenae Museum (in former times this
piece [alike A55] was
in the museum in Nafplion/Nauplia/Nauplion (Pers. comm. G. Chronis
)) and The
British Museum (ground floor of the museum, just outside Room 11,
A53, A54, A55 and possibly A56 and A57 [Pryce])
have fragments available.
A53, A55, 1322, 1470, 1479 have all the same color: old pink (rosso
antico) and some grey vains.1322 is though less wide (missing the bead
border) than A53.
1433 is more Bordeaux red and the relief is less pronounced as A55 or
A51, A52 and A54 have the same color: grayish green.
The apex of the triangle (in Athens,
#1470) has on the right (but
also on the left side) a clear ridge.
A sketchy picture of the apex
Such a ridge is not seen on other
fragments seen in London (such as
but it has a uneven surface in the middle band on the right side) or
(such as #1479).
If all these fragments are part of Treasury of Atreus, I don't know.
- A reconstrution of the facade can be seen below (other
reconstructions are made, but it seems the below one is the most recent
(compiled by Mylonas  page 63,
and incorpoartes ideas of Chipiez, Perrot, Marinatos and Wace):
The facade of Treasury of Atreus (after Mylonas )
The above reconstruction has the apex
spirals wrong (using #1470 as the template): The three (or more?) rows
of spirals in the apex have: on the
row; clock wise single spirals (with in the middle a clear depression,
for an ornament?); on the middle row anti clock wise double spirals;
the third row is unknown.
So my reconstruction can be seen below (partially using Chipiez,
Donaldson, Marinatos, Mylonas, Perrot and Wace):
The facade of Treasury of Atreus (after Reijs )
- A building at the same location as Treasury of Atreus was
destroyed when building the Treasury (Wace ,
page 130). Was this a building that already utilized the possible
- I got a very interesting quote through Peter
Hastings from Robert
book 'The Greek Myths Complete Edition' (Chapter 111 Point 2)
the myth of Thyestes and Atreus:
"Thyestes pointed out that the sun always rose in the Ram at the
Spring festival - hence the story about the golden lamb - but the
Atreus did better: he proved that the sun and the earth travel in
directions, and that what appear to be sunsets are, in fact, settings
the earth. Whereupon the Argives made him king (Lucian: On Astrology
Polybius, quoted by Strabo: i.2.15) Hyginus and Servius both agree that
Atreus was an astronomer, but make the first to predict an eclipse of
sun mathematically, and say that when the calculation proved correct,
jealous brother Thyestes left the city in disgust (Hyginus: Fabula 258;
Servius on Virgil's Aeneid i.572). Socrates took the myth more
regarding it as evidence of his theory that the universe winds and
itself in alternate cycles being accomplished by great destruction of
life (Plato: The Statesman 12-14)."
This could point to some sanity in having an alignment in a building
constructed around the time of Atreus.
- A quote from Hesiod (Works
and Days, considered to be
700 BCE) clearly refers back to the importance of equinox:
line 561: "Keep all the warnings I give you, as the year is
and the days become equal with the nights again, when once more the
mother of us, bears yield in all variety."
The article of Aveni and Ammerman (,
page 87) talks about "This is one of the most telling passages in
poem for it directly suggests that time was being kept by watching the
movement of the Sun along the horizon from day to day."
- Some people say that the triangular structure was closed up
and that the whole dromos (and thus the whole monument) would have
been fill in with sand (as custom: although on the sign of Treasury of
Atreus it says explictly that the dromos was not filled in). This is
then used as an argument that there is
no significance on for instance a possible alignment.
but having everything filled in by sand will not deny that they build
whole structure and thus in my humble opinion, every aspect might hold
something about the culture that made it (even if we now think every
thing was filled-up by sand). I am sure it was open for many years to
that this magnificent building was seen to impress. See also the
article of D.
It is the only tholos that can be seen from the palace.
- There could very well be a link with the Minoan culture at
the time the Treasury of Atreus was build (1250 BCE). In that case it
is interesting to see that the Minoan graves are
directed to eastern and western directions, so also here is a
possible equinox relation. There are some 500-600 graves also around
Mycenae; a study of their directions could be very worthwhile!
Possible geographical alignment at
In the Tholos of Clytemnestra (some 500 m more to the north of
Treasury of Atreus and build around 1225 BCE) the triangular structure
is on the inside fully
up with big nicely cut and fitting stones, but in this case the
dromos points to the south (around 167.8°), and it looks to
aligned with the mythological interesting mound at Nafplion:
If weather permitting also the lower hill of Acronauplia is visible.
The mythology is: Palamides was the son of Clymene (which in turn was
the daughter of Atreus or Catreus) and he died a tragic death, set up
his father (Nauplius)
triangular structure at Tholos of Clytemnestra
Vaguely the hill Palimidi is seen from just above the triangular
in the direction of the dromos
I would like to thank Panagiotis Christias, George Chronis, Gregory
Chronis, Agamemnon Dassis, George
Lesley Fitton, Peter
Karr, David Mason, Natalia Merekoulias, Vassilis Merekoulias, Doug
Shophia Terovola for
helping me in getting
all this information into daylight.
Other interesting links:
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Major content related changes: March 16th, 2004