Moruroa, also historically known as Aopuni, is an atoll which forms part of the Tuamotu Archipelago in French Polynesia in the southern Pacific Ocean. It is located about 1,250 kilometres (780 mi) southeast of Tahiti. Administratively Moruroa Atoll is part of the commune of Tureia, which includes the atolls of Tureia, Fangataufa, Tematangi and Vanavana. France undertook nuclear weapon tests between 1966 and 1996 at Moruroa and Fangataufa, causing international protests, notably in 1974 and 1995. The number of tests performed on Moruroa has been variously reported as 175 and 181.

The Tuamotu Archipelago or the Tuamotu Islands are a French Polynesian chain of just under 80 islands and atolls in the southern Pacific Ocean. They constitute the largest chain of atolls in the world, extending over an area roughly the size of Western Europe. Their combined land area is 850 square kilometres. This archipelago's major islands are Anaa, Fakarava, Hao and Makemo.