| Kletno Bear Cave | |
| Map: | Poland |
| Location: | Kletno, Kłodzko County, Lower Silesia, Poland |
| Coords: | 50.2342°N 16.8342°W |
| Length: | 2000 m |
| Elevation: | 94 m |
| Discovery: | 1966 |
| Entrance Count: | 1 |
| Access: | Public |
| Show Cave Length: | 2000 m |
Kletno Bear Cave (Polish: Jaskinia Niedźwiedzia w Kletnie) is the longest cave located in the Śnieżnik Mountains, which are part of the greater Sudeten mountain range. It was discovered in 1966, near the village of Kletno in Poland. It is famous for its many excavations of the cave bear (Ursus spelaeus).
The first 200m (700feet) of the cave was discovered in October 1966 during the mining process in the newly established quarry Kletno III. In 1967, new corridors were discovered, including the middle parts Sale pałacowe ("Palace Halls"), and, in January 1972, the lowest parts were discovered. New parts of the cave were uncovered in the years 2014 to 2015. In total, the cave has a length of over 2km (01miles) and is currently the longest cave in the Sudetes.
The cave is situated on the right side of the valley of the stream Kleśnica in the Śnieżnik Mountains, a part of the Sudetes. The cave is located at 790 m above sea level on the slopes of Góra Stroma mountain (1,166.8 m).
Rich bone material of Pleistocene animals was found inside the cave, including mostly mammals such as brown bear, cave lion, hyena, wolf, wild boar, and others. Bones of cave bear were dominant among the bone material, making up almost 90% of all the excavated bones.