"In a small basin in the hills we came the next day (27th October, 1930) upon a circle 27 feet (8.5 metres) in diameter of thin slabs of sandstone, 18 to 24 inches high. Half were lying prone, but the rest were still vertical in the sand. There was no doorway or other sign of orientation, and though we searched within and without the circle, no implements could be found. I understand that other similar circles have been found in the neighborhood of the Gilf Kebir." Major R.A.Bagnold, Journeys in the Libyan Desert 1929 and 1930, The Georgaphical Journal, Vol....