Dedap Cave is a tunnel connecting a bay with calm turqoise waters to a doline intermittently filled with marine or brackish water. The cave developed within the Setul Formation. During a high tide, the cave is accessible by small boat. The cave is a short tunnel with a shallow stream running through.
The doline is surrounded by limestone cliff and functioned as a mangrove fringe and wetland forest. Based on aerial photographs and topography map, a major lineament can be traced running through the cave, and very likely that the cave has been formed by the action of sea waves beating through the lienament over thousands of years.
Through the cave, one gets a stunning view of the bay and the islands across.