Yap, also known as Wa'ab by locals, is an island in the Caroline Islands of the western Pacific Ocean. It is located in Yap State of the Federated States of Micronesia. Yap's indigenous cultures and traditions are still strong compared to other neighboring islands. The island of Yap actually consists of four continental islands (hence the alternative name of the Yap Islands). The four are very close together and joined within a common coral reef and entirely formed from an uplift of the Philippine Sea Plate. The land is mostly rolling hills densely covered with vegetation. Mangrove swamps line much of the shore. An outer barrier reef surrounds the islands, enclosing a lagoon between the fringing barrier reef.