Stonehenge surrounded by mysterious buried monuments   …   One of the most striking discoveries was also one of the oldest: a long burial mound dating from before Stonehenge was built between 5000 and 4000 years ago. The mound was built over the remains of a huge, 6000-year-old timber building thought to have been a “house of the dead”, used to store bodies that had been ritualistically defleshed and disassembled. The building has a slightly trapezoidal shape, similar to much older buildings on mainland Europe, although those were always in or near settlements.

The nearby Durrington Walls “super-henge” holds even more secrets.  At almost 500 metres across, it is one of the biggest earthworks of its kind.

Stonehenge stones being repositioned during restoration work in 1914   …   Note the equipment and the safety practices….


What are the dates of the equinoxes?


Ancient Astronomical Alignments   …   Exploring Solar Alignments with Simple Mathematics and Geometry

Boulder Monuments of the Great Plains (SK)

Canada’s Stonehenge

Equinoxes and Solstices

Math Resources for Students and Parents   

Math and Physics Books Online (Free)

Medicine Wheels (AB)

North American Sundial Society 

Royal Astronomical Society of Canada  

Six Sundial Projects    

Solar and Heliospheric Observatory (ESA)    

Stonehenge Decoded  

Sundial Primer           

Sundials:  Their Theory and Construction

Sun Path Chart Program    

Time Fact Files 



Canada’s Stonehenge

by Gordon R. Freeman 

Kingsley Publishing, 2009  (ISBN 978-0-9784526-1-2)

Much has been written over the last forty years regarding the exquisite Mayan tropical calendar in Central America.  The Mayan calendar included cycles of the Sun, Moon, and Venus.  It had a 260 day sacred almanac, a 365-day secular calendar, a 584-day Venus cycle, and a 52 year (18,980 day) Calendar Round, which meshes 73 x 260-day sacred cycles with 52 x 365-day secular years.  The unusual 260-day cycle is made of 13 rounds of 20 named-days, named for various animals, plants, and objects such as a flint knife and a storm cloud.  These divisions are far from random:  20 is the number of fingers and toes we have, while 13 is a prime number that is considered mystical by several cultures. 


Vincent Malmstrom, in his 1997 book Cycles of the Sun, Mysteries of the Moon, traced the 260-day sacred Mayan cycle to an earlier tropical culture at 14°.8 N latitude.  At that latitude, 260 days corresponds to the time from when the Sun passes vertically overhead on the way south on August 13, to when it returns there on the way back northward on April 30.  Ingenious detective work led Malmstrom to conclude that the 260-day sacred almanac originated on the Pacific coastal plain in Izapa, Mexico, at a date earlier than the Maya Classical Period, and that Day 1 in the almanac was August 13, 1359 B.C.  During the next two millennia, this calendar and associated sacred geometries diffused northerly, westerly, and easterly from Izapa and was adopted by subsequent civilizations. 

By contrast, a Mayan Long-Count calendar of 360-day years extrapolates to a beginning in 3114 B.C. 


During the 1970’s, John Eddy, an astronomer from Colorado, along with two archaeologists, Tom and Alice Kehoe of Saskatchewan, studied a number of geoglyphs and concluded that two of the medicine wheels have features that point to the Summer Solstice Sun rise.  The older of these two is the Moose Mountain Medicine Wheel (49°.76 N, 102°.70 W) on a hill east of Weyburn, Saskatchewan, estimated at two to three thousand years old.  On the flat plain of southeastern Saskatchewan, a ridge of hills that reaches 200 meters above the plain seems like mountains, but it’s actually a terminal moraine from glacier meltback.  The second medicine wheel oriented toward the Summer Solstice Sun rise has a spectacular setting on a real mountain, 1800 meters above the plain, on Medicine Mountain in the Big Horns of Wyoming.  The Big Horn Medicine Wheel (44°.83 N, 107°.92 W) is relatively new, only a few centuries old.


I had found Summer and Winter Solstice Sun rise and set observation lines between cairns and rocks that mark the first- or last-flash directions, with tiny errors of less than one-fifth of a Sun-diameter.  Along a particular alignment, the Solstitial Sun rise or set from year to year occurs at the same place on the horizon within less than one-tenth of a degree.  The enormous Ómahkiyáahkóhtóohp complex contains several observation lines for each of the season dates. Some lines are several kilometres long, others less than 100 metres; some are horizontal to a distant horizon, and others slope a few degrees upward to a near horizon to avoid a thin layer of cloud on a distant horizon.  It seems that during the last 5000 years, more than one society built its own lines for the same season-pivot dates.  The Sun-standstills, at the northerly and southerly extremes of rise and set directions, are the most obvious characteristics of the Sun’s annual cycle along the horizon.  These markings were quite easy to find.  I then looked for alignments that mark the Equinox Sun rise and set directions.  After initial failures, I increased the chance of finding them by loosening the error restriction to one Sun diameter, half a degree. 

I found none. 


We found alignments of stones that marked the rises and sets three days before the Equinox in March, and three days after the Equinox in September.  Puzzling. 


The [Astronomical] Almanac shows that at the latitude and longitude of Ómahkiyáahkóhtóohp, 51°N and 112°W, the night of March 17 to 18, 1991, was less than half a minute from exactly twelve hours long, the Equalnight.  The other Equalnight in 1991, September 25 to 26, was also less than half a minute from exactly twelve hours long.