The Islas Marias occupy an area of 245 km ². Up to the present times, they have served its original purpose - they have been a penal colony. The prison had been established on the largest island, Isla Maria Madre (126 km2) , in 1905. The other islands, Isla María Magdalena, Isla María Cleofas and Isla San Juanito, are uninhabited. The Islas Marias were discovered in 1532 by a nephew of Hernan Cortez, named Diego Hurtado de Mendoza, who named them Magdalene´s Islands.Three of the islands were named after three Marys in the Biblical New Testament: Mary the mother of Jesus, Mary Magdalene, and Mary the wife of Cleopas. There is also a Catholic church on the islands. Islas Marias are mostly covered with subtropical virgin forest, here and there you would find grassland and shrubs. The islands have been kept aside civilization progress so they are a habitat to various rare species of animals and birds, hence protected by the UNESCO. They are widely known as a nesting place of seabirds. 11 endemic species of mammals have been registered within the territory of Islas Marias (e.g. raccoon, rabbit) .