At a distance of 1 mile W of cape Mavrolímni the namesake lake is formed, with a road right on its shore. It owes its name (meaning "black lake") to its volcanic, dark bottom. In ancient times it was known as Gorgópis or Exchatiópis. It has a depth greater than 50 m. In 1981, an earthquake made a large piece of land, which separated the lake from the sea, subside.

Its entrance, marked by a green and a red light, is open N, has a width 30 m and depths of 0.7–2 m along the entrance axis. The N and W inner coasts of the lake are quayed and have depths of less than 1 m near them. Crafts before entering should contact the lakes port authorities in order to receive berthing instructions.