Revillagigedo Islands or Revillagigedo Archipelago (rāvē`yähēhā`thō), volcanic island group in the Pacific Ocean, c.450 mi (720 km) W of Colima state and S of Baja California, Mexico. The islands, which are under federal jurisdiction, are part of submerged range of volcanic mountains. Socorro (110 sq mi/285 sq km) is the largest island; except for a small number of naval personnel the islands are uninhabited. A volcano on San Benedicto island rose suddenly in 1952. The Mexican flag was officially raised over the islands in 1957. In 2017 some 57,000 sq mi (150,000 sq km) of the surrounding waters were declared a marine reserve and national park.