is an island in West Nusa Tenggara province, Indonesia. It forms part of the chain of the Lesser Sunda Islands, with the Lombok Strait separating it from Bali to the west and the Alas Strait between it and Sumbawa to the east. It is roughly circular, with a “tail” (Sekotong Peninsula) to the southwest, about 70 kilometres (43 miles) across and a total area of about 4,514 square kilometres (1,743 square miles). The provincial capital and largest city on the island is Mataram. It is somewhat similar in size and density with neighboring Bali and shares some cultural heritage, but is administratively part of Nusa Tenggara Barat along with sparsely populated Sumbawa. It is surrounded by a number of smaller islands locally called Gili.The Lombok Strait lies to the immediate west of the island, marking the passage of the biogeographical division between the prolific fauna of the Indomalayan ecozone and the distinctly different, but similarly prolific, fauna of Australasia—this distinction is known as the “Wallace Line” (or “Wallace’s Line”) and is named after Alfred Russel Wallace. Wallace was the first person to comment on the division between the two regions, as well as the abrupt boundary between the two biomes.