Buton Island seems to be small compared to its neighbor Sulawesi, but with slightly more than 4,400 square kilometers (just under 1,700 square miles) it is Indonesia’s 19th largest island. Much of the lowland consists of uplifted karst and other limestone formations. Due to its hilly topography it still has a considerable amount of forest; most of it is seasonal tropical lowland forest with mangroves in coastal areas. Visitors to Bau-Bau, the main city on Buton Island, may well be welcomed with a mangaru, which is a welcome dance performed by three men to respect guests and to ward off enemies. Overlooking Bau-Bau is Benteng Keraton Buton, known as having been the seat of the sultan. Claiming to be the biggest fort in Indonesia and made of coral blocks, it commands an excellent view over the city and port and the sea beyond.