Sulawesi, an Indonesian island east of Borneo, comprises several long peninsulas radiating from a mountainous center. It’s known for coral reefs and dive sites such as Bunaken National Park, the Togian Islands and Wakatobi National Park. Its largest city is Makassar, home to Fort Rotterdam, a former Dutch fort now housing 2 museums. Outside Makassar, Leang-Leang Historic Park preserves prehistoric cave paintings.