Hellhole, a massive, spectacular cave in Germany Valley (Pendleton County), is one of the most famous wild caves in the eastern United States. The entrance is a large sinkhole that drops 160 feet into an enormous main chamber.

The first recorded descent was made in 1929 using a windlass and steel cable. Spelunkers have mapped 22.1 miles of passages, and many cavers believe its total length could be over 50 miles. The cave features huge rooms and passages beautifully decorated with stalactites and stalagmites.

Hellhole isn't just a huge cave—it's one of the most important bat habitats in the entire eastern United States. The cave hosts a massive hibernating colony of over 100,000 little brown bats. It is also a critical home for large numbers of federally protected and endangered bats, including the Indiana bat and the Virginia big-eared bat.

To protect these vulnerable and essential populations, the U.S. Fish and Wildlife Service fenced the entrance in 1981. The cave remains closed to visitors to ensure the survival and safety of these endangered species.