Tuvalu, formerly known as the Ellice Islands, is a Polynesian island nation located in the Pacific Ocean, midway between Hawaii and Australia. Its nearest neighbours are Kiribati, Nauru, Samoa and Fiji. It comprises four reef islands and five true atolls. Its population of 12,373 makes it the second-least-populated sovereign state in the world, with only Vatican City having fewer inhabitants. In terms of physical land size, at just 26 square kilometres (10 sq mi) Tuvalu is the fourth smallest country in the world, larger only than the Vatican City at 0.44 km2 (0.17 sq mi), Monaco at 1.95 km2 (0.75 sq mi) and Nauru at 21 km2 (8.1 sq mi).