Isla Rasa - Mexico
Isla Rasa is very flat and very small island in the Sea of Cortez, but as many as half a million birds nest on this island at once. Almost all the Heermann's Gulls and Elegant Terns in the world go there to breed - the Heermann's Gulls from as far away as British Columbia and the Elegant Terns from Peru and Chile. It lies between Isla Angel de la Guarda and Isla San Lorenzo, west of Isla Tiburon, approximately 37 miles (60 km) southeast from Bahia de los Angeles, Baja California. It consists mainly of low hills of volcanic rock and large valleys with deep guano deposits. The island shores are rocky with cliffs mainly in the eastern side and three tidal lagoons on the western side, one of them directly connected with the ocean.