An island in the Central Dalmatian island group 4 km southwest of the island of Vis. Its highest point is Strazbenica (239 m). A few permanent and several seasonal inhabitants live in the small settlements of Salbunara, Mezuporat and Porat on bays of the same names, and the settlement of Potok on a small plain at the top of the island, contains vineyards and olive groves.

The coast is lined with several caves accessible from the sea, the most famous of which is Modra spilja (Blue Cave) on the Balun Bay. It became famous in 1884 and has been compared to the Grotta Azzura Cave on the island of Capri in Italy. The sun's rays that penetrate the cave through an underwater opening are refracted and reflected from the bottom, illuminating the cave with a silvery blue light. Because of this phenomenon, the best time to visit the cave is between 9:30 and 11:30 am. The cave is accessible from the sea by boat or by diving through the underwater opening. Several houses on the island can be rented for vacationing.

The Benedictine Monastery of sv. Silvestar (St. Sylvester) was established in 1050, but was abandoned 200 years later due to the danger of pirate attacks. The monks moved to Komiza on the island of Vis. Mezuporat is an wide, open cove with an anchorage at a depth of 8 m. Boats can berth in the small harbour which is usually occupied. This is the main starting point for people visiting the Modra spilja.

Porat (or Bisevska luka) is a narrow bay with a sandy beach and a small 1.5-m-deep harbor at the end. Due to the shallowness of the sea, boats cannot anchor near the beach. The bay is exposed to southwesterly and westerly winds. When they blow, it is advisable to leave the bay. The Porat Bay is a frequent destination of tourist ships from Komiza. Salbunara is a narrow bay with a sandy beach and a 20-m-long and 1.5-m-deep harbor. As in the case of the Porat Bay, it is advisable to leave when southwesterly and westerly winds blow.