Located in the South Pacific Ocean, 2,400 kilometres (1,500 mi) northeast of New Zealand, Niue (NIU) is situated in the middle of the Pacific within a triangle boundary of Tonga, Samoan, and the Cook Islands.  Niue is a single island that is well known as one of the largest upraised coral atolls in the world. The terrain consists of steep limestone cliffs along the coast with a central plateau rising to about 60 metres (200 ft) above sea level. A coral reef surrounds the island, with the only major break in the reef being on the central-western coast, close to the capital, Alofi.