Curaçao is a long, arid, and generally flat island, stretching some 64km from southeast to northwest. It is 16km wide at its widest point and has an area of 472km². It is the largest island in the Netherlands Antilles group. Together with Aruba to the west and Bonaire to the east, Curaçao forms the ABC group.
The long north coast of Curaçao is characterized by a rough coastline. The west end of the island is also characterized by extensive hilly terrain, most of it encompassed by Christoffel Park with the highest mountain of Curaçao, Mt. Christoffel (377m asl). The east end of the island is mostly barren plain, with few settlements.
Curaçao is more or less formed on limestone formations set on top of eons-old volcanic rock. A coral reef that grew on top of a submarine volcano during millions of years, because of a continual subsidence of the volcano and the sea floor. But when the sea level dropped because of the Ice Ages, the coral reef formed the island of Curaçao and the limestone of the reef was subject to weathering. Caves were formed since then, along preexisting reef caverns in the limestone.