Tubuai is the name of a group of islands and also the name of its main island, being part of the Austral Islands, French Polynesia, in the Pacific Ocean. Tupua'i, the main island of the Tupua'i Island group, It is 640 km (400 mi) south of Tahiti. It sustains a population of 2,049 people on 45 km2 (17 sq mi) of land. Due to its southerly position, Tupua'i has notably cooler weather than Tahiti.
The island is ringed by a lagoon formed by an encircling coral reef. A break in the reef that enables passage for ships is located on the North side of the island. Tubuai has two volcanic domes, with its highest point, Mt Taita'a, being 422 meters (1380 feet). A number of small islets or keys called motus in Polynesian, lie along the reef that enclose the island. These were described in the late 1700s as having an abundance of Toa trees, which the native islanders used in housebuilding and in making war clubs and spears due to the wood's density.