The relief is not very pronounced. It takes in three areas: the flat region of the Pla, where the town of Manacor stands; the Serra de Llevant, characterised by its soft relief; and the Marina, which is formed by white gritty stone and inclines down to the sea. These limestone karsts have favoured the appearance of caves. The most outstanding for their beauty are the Dragon Caves and the Fishhook Caves. Near the coast, there is one of the longest underwater caves known in Europe : the Gleda-Camp des Pou system. It has more than 13 km in length.