Sixteen kilometers east of the Sea of Galilee in the western part of the historic Bashan plain of the Golan Heights (a contested area claimed by both Syria and Israel) are the ruins of a most unusual structure, which scholars believe was built at least in part for archaeoastronomical purposes. Located at 515 meters above sea level, Rujm el-Hiri consists of a central cairn with a set of concentric rings encircling it.
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 40,000 tons of uncut black volcanic basalt field stones piled and wedged into between five and nine concentric rings (depending on how you count them), with heights reaching to 1 to 2.5 meters (3-8 feet) high.
Nine Rings at Rujm el-Hiri
The outermost, largest ring (Wall 1) measures 145 meters (475 feet) east-west and 155 m (500 ft) north-south. The wall measures consistently between 3.2-3.3 m (10.5-10.8 ft) thick, and in places stands up to 2 m (6 ft) in height. Two openings into the ring are currently blocked by fallen boulders: the northeastern measures some 29 m (95 ft) wide; the southeastern opening measures 26 m (85 ft).
Not all of the internal rings are complete; some of them are more oval than Wall 1, and in particularly, Wall 3 has a pronounced bulge to the south. Some of the rings are connected by a series of 36 spoke-like walls, which make up chambers, and seem to be randomly spaced. At the center of the innermost ring is a cairn protecting a burial; the cairn and burial come after the initial construction of the rings by perhaps as long as 1500 years. The cairn is an irregular stone heap measuring some 20-25 m (65-80 ft) in diameter and 4.5-5 m (15-16 ft) in height.
Dating the Site
Very few artifacts have been recovered from Rujm el-Hiri, and no suitable organic materials have been recovered for radiocarbon dating. Based on what little artifacts were recovered, the earliest constructions were the rings during the Early Bronze Age, of the 3rd millennium BC; the cairn was built during the late Bronze Age of the late 2nd millennium.
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 Aveni and Mizrachi 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. Calculations of when the astronomical alignments would have matched stars supports the dating of the rings at having been built at about 3000 BC +/- 250 years.
The walls at Rujm el-Hiri 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.
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.
Polcaro A, and Polcaro VF. 2009. Man and sky: problems and methods of Archaeoastronomy. Archeologia e Calcolatori 20:223-245.
Neumann F, Schölzel C, Litt T, Hense A, and Stein M. 2007. Holocene vegetation and climate history of the northern Golan heights (Near East). Vegetation History and Archaeobotany 16(4):329-346.