Emine Bair Hosar, Natural cave in Chatyr-Dag massif, Crimea, Ukraine

Emine Bair Hosar is a vertical karst cave on the lower plateau of the Chatyr-Dag massif, 125 m deep with 1,460 m of passages. Its Main Hall, reached through the North Gallery, has a south wall of multicoloured calcite curtain. Above it, the Upper Gallery holds the Ozerny Hall and the Idol Hall, ringed by more than a hundred stalagmites.

The cave was first descended in 1927. In the 1970s and 1980s speleologists opened several hundred metres of new halls and galleries, bringing it wider renown. Its passages now total 1,460 m, with a depth of 125 m. The entrance was built by cavers on the bed of the ancient river that carved the cave.

The Crimean Tatar name Emine Bayır Hasar combines Emine, a common Tatar woman's name, with bayır (hill) and hasar (funnel or collapse pit), giving "the funnel of Emine's hill". A Ukrainian reading instead glosses Emine as "oak", yielding "the well on the hillside under the oak". The halls visitors walk through carry their own names: Ozerny, Idolov, Sokrovishchnitsa and Kechkemet.

The main entrance follows an ancient riverbed passage that leads into the cave's interior sections. Visitors should expect uneven ground and some inclines, so sturdy footwear is recommended.

The cave houses a paleontological museum displaying skeletons of extinct animals like mammoths and woolly rhinoceroses found within the site itself. These fossils give visitors a rare look at the prehistoric fauna that once inhabited the region.