Ohalo II

Ohalo II is a hunter-gatherer camp on the southwestern shore of the Sea of Galilee in Israel, dated to about 23,000 calibrated years before present. It came to light in 1989, when a long drought lowered the lake by about 9 m (30 ft). Dani Nadel of the University of Haifa led excavations in 1989-1991 and 1999-2000. Because the remains were sealed under water, the site preserves the floors of brush huts in unusual detail.

The huts

• Number: six oval rings of charcoal mark where the dwellings stood.
• Size: about 2.7 to 4.9 m (9 to 16 ft) long.
• Materials: branches and brushwood. The simple design probably took only a few hours to put up.
• Hearths: located outside the huts rather than inside.

The best-studied dwelling, Hut 1, was analysed by Nadel and Ella Werker in a 1999 paper in Antiquity describing the plant remains of a brush hut, which they then dated to about 19,000 years ago on an uncalibrated radiocarbon scale. The floor of Hut 1 produced more than 90,000 seeds of over 100 species, a grinding stone about 40 cm (16 in) long set on a sand and cobble base, and 132 retouched flint tools concentrated near the entrance. The excavation also produced some of the earliest known evidence of plant bedding.

How it survived

The camp burned after a short occupation, probably a few generations at most. Rising water then covered it, and fine clay and silt sealed the charred remains. Low-oxygen conditions slowed decay for millennia. The site covers a large area and may extend beyond what has been excavated.

Significance for roofing history

Ohalo II is often cited as the oldest known example of brush dwellings. It shows a light structure of branches forming both wall and roof, the kind of shelter that ethnographic records suggest was used widely by mobile groups. Most comparable sites have left only post holes; at Ohalo II, the burnt plant matter itself survives, which allows the materials to be identified rather than assumed.