The island of Susac is located in the central part of the Adriatic, about 23 km west of the island of Lastovo and 45 km southeast of the island of Vis. On this small island with an area of 4 square kilometers, the main ridge of the island extends from northeast to southwest, where a lighthouse stands above Cape Kanula. The northernmost point of the island is Cape Nazene and the southernmost Cape is Lastovac. On the northeast is the highest peak of Veli Gark 243 m asl. There are steep ditches on the northwest coast and several sandy coves in the southeast.
Mediterranean shrubs only grow on the highest ridge and northern slopes. The southern slopes are opposed to tropical vegetation.