Arrecife Alacranes National Park, Marine national park and Ramsar site in Yucatán, Mexico

Arrecife Alacranes National Park is a protected marine area in Yucatán centered on five islands in the Gulf of Mexico: Isla Pérez, Isla Blanca, Isla Muertos, Isla Pájaros, and Isla Desterrada. The coral reef system is the largest of its kind in this part of the gulf and supports diverse fish, sea turtles, and other marine life.

The reef appears in navigation charts from the 16th century; Pedro Mártir de Anglería described it in 1521, and its name may come from an account by Gonzalo Fernández de Oviedo y Valdés. The national park was decreed on 6 June 1994, added to UNESCO's World Network of Biosphere Reserves on 27 October 2006, and listed as a Ramsar site on 2 February 2008.

The name Alacranes, Spanish for scorpions, is traced in the sources to a story by Gonzalo Fernández de Oviedo y Valdés in his Historia General y Natural de las Indias. The reef appears on charts from the 16th century as a hazard for coastal shipping, and Pedro Mártir de Anglería recorded it in 1521. Today Isla Pérez holds a CONANP field station and a small Mexican Navy detachment of 14 marines, rotated monthly, alongside three lighthouse keepers.

Visitors need a permit before entering the park, and boat tours depart from Puerto Progreso. The best time to visit is during months with calmer seas, when conditions for reaching the islands are most favorable.

The lighthouse on Isla Pérez is often said to have been donated by Queen Victoria in 1900, but construction was ordered by Mexico's Secretaría de Comunicaciones in June 1899 and finished in 1901. The confusion likely comes from the maker's plate of Chance Brothers & Co. Ltd of Birmingham. A Secretaría de Marina detachment of 14 marines and three lighthouse keepers rotates through the island.