Deer Cave in Gunung Mulu National Park (Borneo)
Deer Cave is a passage about 150 m (500 feet) in diameter and about 1 Km (0.6 Miles) long, opened on both end. It was, for many years, considered the largest single cave passage in the world.
This photo was taken not far from the mouth of the cave.
For more photos and information about Deer Cave, go to my Deer Cave photo series.