Maas Popaya Raja Island's Nature Reserve is a nature reserve located in North Gorontalo Regency, Gorontalo. Maas Popaya Raja Island's Nature Reserve covers 3 islands namely Mas Island, Popaya Island and Raja Island. This nature reserve was designated as a protected area on October 17, 1939 during the reign of the Dutch East Indies. The land area is 159.4 hectares.
The designation of this area as a nature reserve is intended for turtle protection. There are seven types of turtles in the world, four of which make Maas Popaya Raja Island's Nature Reserve a nesting location. The four types of turtles are the hawksbill turtle (Eretmochelys imbricata), green turtle (Chelonia mydas), loggerhead turtle (Caretta caretta), and leatherback turtle (Dermochelys coriacea).
The vegetation formed in the Maas Popaya Raja Island's Nature Reserve is a tropical rain forest. In coastal areas, mangrove forests of the Rhizophora buguira species can be found. Several types of fauna that live in this nature reserve include green turtles, leatherback turtles, albatrosses, bats, deer, rats, king prawns, kumkum, cuscus, monitor lizards, storks, green snakes, and pythons.