The mouth of 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.
For more photos and information about Deer Cave, go to my Deer Cave photo series.
Photo processed in True Tone HDR with Tone Mapping from a single RAW exposure.