Tongatapu is the main island of Tonga and the site of its capital, Nukuʻalofa. It is located in Tonga's southern island group, to which it gives its name, and is the country's most populous island, with 74,611 residents (2016), 70.5% of the national population, on 260 square kilometres. Tongatapu is Tonga's centre of government and the seat of its monarchy.