Hohlenstein-Stadel, Prehistoric cave in the Lone valley, Germany

Hohlenstein-Stadel is a cave in the Hohlenstein limestone cliff on the southern rim of the Lone valley, near Asselfingen. Its entrance is 8 m wide and opens on the north side of the massif; inside, a single curved gallery about 70 m long, with a vault averaging 4 m high, is lined with small chambers and side bays. The cave lies 5 m above the Lone and reaches 470 m in altitude.

Oskar Fraas made the first excavations in 1861, searching for cave bear bones. On 25 August 1939, Otto Völzing found over 200 broken ivory pieces that were stored at the Museum Ulm until 1969, when Joachim Hahn assembled them into the 31-cm Löwenmensch, a humanoid with a lion's head dated to 35,000–40,000 years ago. A Neanderthal femur found in 1937 in a Mousterian layer was sequenced in 2017. The site joined the UNESCO World Heritage list in 2017.

The name Stadel means "barn", and in 1866 the palaeontologist Oskar Fraas called the cave a "bear menagerie". Visitors can see the 8-metre-wide entrance on the north side of the Hohlenstein cliff, above the Lone. The cave has yielded mammoth-ivory pendants and perforated animal teeth from the Aurignacian.

The cave opens on the north side of the Hohlenstein massif at 470 m, about 5 m above the Lone and some 100 m south of its banks. Reach it via the Lonetalweg, off the K7307 road between Öllingen and Bissingen an der Teck. The entrance is 8 m wide; inside, a single curved gallery runs about 70 m with side chambers under a vault averaging 4 m high.

The 88 cave bear skulls were found not in the Stadel but in the neighbouring Bärenhöhle, a few metres away, where Oskar Fraas recorded 10,000 cave bear bones in 1861. In the Stadel itself, Fraas found only scattered lithic artefacts and complete bear bones in 1866.