At the top of the hill, there was a large stone known as the altar stone. It was first mentioned by Georg Christoph Pisanski in 1769. According to an 1867 description by Otto Glagau, the stone had a flat top and measured about 15 cubits (approximately ) in diameter. The taller side measured and the lower . According to Eduard Gisevius, the stone had carvings of a sword, human hand and feet, animal footprints, and something that resembled a Greek temple. This information is dubious as Gisevius wrote many years after the destruction of the stone and no other account mentioned the markings.