Tongatapu is the largest island within Tonga, home to the capital city of Nuku‘alofa. Fua’amotu airport is on the Southern side, but can be reached easily, only a half hour drive from the city.
If you’re looking for things to do in Tongatapu, there’s plenty on offer. There’s an abundance of small islands just off the coast which are fantastic for snorkeling and diving. Pangaimotu can be reached by a quick 10 min boat trip and hosts a fantastic wreck to explore off the main beach.
If history is more your thing you can stop in at Captain Cooks landing point from 1773, or explore the Ha’amonga’a Maui Trilithon, an artifact said to be constructed by the Tongan god Maui. The Royal Palace is also located on the Northern shoreline, looking out North-East over the other islands which make up Tonga.