Drach Caves

The Caves of Drach are four great caves that are located in the island of Majorca, Balearic Islands, Spain, extending to a depth of 25 m and reaching approximately 4 km in length. They are in the municipality of Manacor, near the locality of Porto Cristo. They were first mentioned in a letter dated 1338. The four caves, called Black Cave, White Cave, Cave of Luis Salvador, and Cave of the French, are connected to each other.

The caves have formed by water being forced through the entrance from the Mediterranean Sea, and some researchers think the formation may date back to the Miocene Epoch. There is an underground lake situated in the caves called Martel Lake, which is about 115 m in length and 30 m in width, and its depth varies between four and twelve meters.

Source: Wikipedia