An isthmus, Mavis Grind (), about a hundred yards across, forms the sole connection with the rest of Mainland. The coast is indented by numerous bays and consists largely of high, steep rocks. It has a number of high, fissured, cavernous cliffs on the west coast and consists of many skerries, islets, and offshore rocks. The interior has a very small amount of arable land; it consists mostly of rough, rising ground, including Ronas Hill, the highest point in all Shetland.