Yap, in Yap Wa'ab or Waqab, is one of the four states of the Federated States of Micronesia. It is the most western of the country. It comprises 139 islands spread over 1,137 km, mostly assembled in archipelagos and belonging to the Caroline Islands. The largest archipelago is that of the Yap Islands. The latter, located in the Philippine Sea, is home to most of the state's population and the capital, Colonia, located on the island of Yap in the municipality of Weloy. With a surface area of 121.7 km2, Yap is populated by 11,376 inhabitants in 2010: its population is mixed with Oceanians, Europeans and Japanese. Yap is the official and main language.