The limestone of the hills is actually called karst. This topography is caused when layers of bedrock made up of a soluble substance such as dolomite or in this case limestone. The landscape has been slowly eroded through a process called solvation. The hills are that which is left behind.
At first site these amazing hills on the island of Bohol look as if Willy Wonka and his Oompa Loompas have upped sticks and relocated. However, although local people have their own legends as to the presence of the conical shaped hills, reality is somewhat different.