Situated in a Sabah Forestry Department forest reserve, the caves and the surrounding area are a protected area for wildlife, especially orangutans.

The main cave system is divided into two parts: the more accessible Simud Hitam (Black Cave), and the larger Simud Putih (White Cave) which lies above. The names refer to the main type of nests produced by swiftlets in each cave.

The cave system is home to many other animals, including massive populations of cockroaches and bats. Outside one can see many raptors including crested serpent eagles,kingfishers, and Asian fairy-bluebirds. Access is in the form of a wooden walkway circuiting the interior.