A Pacific island archipelago off Nayarit, Mexico, recognized by UNESCO as a biosphere reserve with a complex penal and ecological history.
Islas Marias
The Islas Marias are a group of islands in the Pacific Ocean, located roughly 112 kilometers off the coast of the Mexican state of Nayarit. The archipelago is made up of four main islands, Maria Madre, Maria Magdalena, Maria Cleofas, and San Juanito, along with several smaller islets, covering a combined surface of nearly 245 square kilometers.
Although long associated with the federal penal colony that operated on Isla Maria Madre from 1905 until 2019, the islands today are defined primarily by their protected natural status. In 2010, UNESCO designated the archipelago as a biosphere reserve in recognition of its fragile ecosystems, endemic species, and isolation from the Mexican mainland. The current identity of the Islas Marias hinges on conservation, ecological research, and a measured form of nature-based tourism rather than mass visitation.
The landscape combines subtropical climate, rugged volcanic topography, and surrounding marine habitat, supporting endemic flora and fauna and a rich marine ecosystem. While only Maria Madre remains inhabited, the islands as a whole form one of the most distinctive Pacific island territories of Mexico and a key reference point in the country's system of protected natural areas.
