Panglao has a terrain that ranges from plain, hilly to mountainous. Panglao is made of Maribojoc limestone, the youngest of the limestone units found in the western area of Bohol. The limestone composition delayed the development of the international airport as coralline limestone is soluble which causes formation of caves and sinkholes. One interesting geological feature found in the island is the Hinagdanan Cave which has an underground water source. The cave is an important water source as the island has no rivers or lakes.