is a very small island nation located in the South Pacific Ocean in the region of Oceania. Nauru is the world's smallest island country at an area of just 8.5 square miles (22 sq km). Nauru had a 2011 population estimate of 9,322 people. The country is known for its prosperous phosphate mining operations in the early 20th century. Nauru became independent from Australia in 1968 and was formerly known as Pleasant Island. Nauru has no official capital city.