Tonga, officially the Kingdom of Tonga, is a state and an archipelago in the South Pacific Ocean, comprising 176 islands scattered over 700,000 square kilometres of ocean in the South Pacific. Fifty-two of the islands are inhabited. The Kingdom stretches over a distance of about 800 kilometres in a north-south line located at about a third of the distance from New Zealand to Hawaii.
Located in Oceania, Tonga are divided into three main groups – Vava’u, Ha’apai, and Tongatapu.The largest island, Tongatapu, on which the capital city of Nukuʻalofa is located, covers 257 square kilometres. Geologically the Tongan islands are of two types: most have a limestone base formed from uplifted coral formations; others consist of limestone overlaying a volcanic base.