The Ipf is a mostly treeless mountain, near Bopfingen, Ostalbkreis, Baden-Württemberg, Germany with a prehistoric hill fort on its top.The fort is situated on an isolated hill, with a flattened summit surrounded by a stone wall, ditch and large counterscarp . The overall diameter is about 180 metres. There are also extensive ramparts traversing the slopes to protect a large enclosed area and entranceway. There is evidence of occupation from the Bronze Age through the Iron Age to the early Celtic La Tene period, a span of almost a thousand years .