Haʻapai is a group of islands, islets, reefs, and shoals in the central part of Tonga. It has a combined land area of 109.30 square kilometres (42.20 sq mi). The Tongatapu island group lies to its south, and the Vavaʻu group lies to its north. Seventeen of the Haʻapai islands are inhabited. Their combined population is 5,419. The highest point in the Ha‘apai group, and in all of Tonga, is on Kao, which rises almost 1,050 metres (3,440 ft) above sea level.