The Chocolate Hills is an unusual geological formation in Bohol province, Philippines. There are at least 1,260 hills but there may be as much as 1,776 hills spread over an area of more than 20 mi². They are covered in green grass that turns brown during the dry season, hence the name.
The Chocolate Hills form a rolling terrain of haycock hills – mounds of a generally conical and almost symmetrical shape. Estimated to be from 1,268 to about 1,776 individual mounds, these cone-shaped or dome-shaped hills are actually made of grass-covered limestone. The domes vary in sizes from 98 to 160 ft high with the largest being 390 ft in height. Bohol’s “main attraction”, these unique mound-shaped hills are scattered by the hundreds throughout the towns of Carmen, Batuan and Sagbayan in Bohol.
The Chocolate Hills consist of Late Pliocene to Early Pleistocene, thin to medium bedded, sandy to rubbly marine limestones. These limestones contain the aboundant fossils of shallow marine foraminifera, coral, mollusks, and algae. These conical karst hills, called mogote, are created by a combination of the dissolution of limestones by rainfall, surface water, and groundwater and their subaerial erosion by rivers and streams after they had been uplifted above sea level and fractured by tectonic processes. These hills are separated by well developed flat plains and contain numerous caves and springs. The Chocolate Hills are considered to be a remarkable example of conical karst topography.
Photo Credit: Mikael