Bohol Island

Bohol Island is also called Cave Country, as some 1400 caves have been found so far, an average of 30 caves in each of its 47 towns. There is even a theory about the name Bohol being derived from the caves, as buho means hole in Filipino. However, this word is generally used for holes were spring water emerges, for example, the many karst springs in the coastal towns of the island.

The famous tourist attraction called Chocolate Hills is a typical tower karst. The limestone hills become brown during summer, hence the name. The hills formed by karst processes and are full of caves. Even the colour is a result of karstification, as the limestone has cracks which drain excess rainwater away. During drier periods, the soil is dried out and the rocks below are dry too. There is no groundwater close to the surface, so all plants dry out.

The island emerged from the sea during the mid-Tertiary, about 20-30 million years ago. Since then karstification has progressed. The result is a tropical karst in its late state, also called tower karst.

On the island is the Bohol Island Geopark, which is managed by the Provincial Government of Bohol. It seems you may find some educational signs at interesting spots. Unfortunately their website is quit uninformative. They list only about 16 geotopes, and the descriptions are very short and uninformative.