Oki Islands (隠岐諸島 Oki-shotō?, or 隠岐群島 Oki-guntō) is an archipelago in the Sea of Japan, the islands of which are administratively part of Oki District, Shimane Prefecture, Japan. The islands have a total area of 346.1 square kilometres (133.6 sq mi). Only four of the sixteen named islands are permanently inhabited. Much of the archipelago is within the borders of Daisen-Oki National Park. Due to their geological heritage, the Oki Islands were designated a geopark within the UNESCO-assisted Global Geoparks Network in September 2014.