Devetashka cave

Devetàshka Cave is a large karst cave around 15 km (9.3 mi) southwest of Letnitsa and 15 km (9.3 mi) northeast of Lovech, near the village of Devetaki on the east bank of the river Osam, in Bulgaria. The site was continuously occupied by paleo-humans for tens of thousands of years, served as a shelter for a variety of animal species during extensive periods and is now home to nearly 30,000 bats.