Ancient Astronomy at Rujm el-Hiri

Sixteen kilometers east of the Sea of Galilee in the western part of the historic Bashan plain of Israel are the ruins of a most unusual structure. Built during the late Chalcolithic or Early Bronze Age about 5000 years ago, Rujm el-Hiri (also called Rogem Hiri or Gilgal Rephaim) is made of an estimated 42,000 tons of uncut black volcanic basalt field stones piled and wedged into five concentric rings, about 2 to 2.5 meters high. The outermost, largest ring is 156 meters (475 feet) in diameter, with walls up to 3.5 meters thick. Each ring is broken into compartments by a series of 36 spoke-like walls, which seem to be randomly spaced. At the center of the innermost ring is a cairn protecting a burial; the cairn and burial postdate the initial construction of the rings by perhaps as long as 1500 years.

The huge structure (and a series of dolmens nearby) may be the origin of the myths of the ancient race of giants, mentioned in the Old Testament of the Judeo-Christian bible as led by Og, King of the Bashan. Archaeologists Yonathan Mizrachi and Anthony Aveni, studying the structure since the late 1980s, have another possible interpretation: a celestial observatory.

Summer Solstice at Rujm el Hiri

Recent work by Mizrachi and Aveni has noted that the entranceway to the center opens on sunrise of the summer solstice. Other notches in the walls indicate the spring and fall equinoxes. Excavations into the walled chambers did not recover artifacts indicating that the rooms were ever used either for storage or residence. These walls seem to have pointed to star-risings for the period, and may have been predictors of the rainy season, a crucial bit of information for the sheep herders of the Bashan plain in 3000 BC.

Sources

Weird buildings for tracking celestial occurrences are not only found in Israel; visit Astronomical Observatories for more.

Aveni, Anthony and Yonathan Mizrachi 1998 The Geometry and Astronomy of Rujm el-Hiri, a Megalithic Site in the Southern Levant. Journal of Field Archaeology 25(4):475-496.

To find out more, go to Yonathan Mizrachi's website on Rujm el-Hiri. There is a terrific picture providing a better idea of the sheer scale of the building on the Bible Places website, as well as pictures of other structures in the Golan Heights.