The Formigas Islets (Portuguese: Ilheus das Formigas, literally Islets of the Ants named for the small and dispersed rocks that resemble scattered ants) are a group of uninhabited rocky outcroppings located 43 km northeast of Santa Maria and southeast of Sao Miguel. Due to strong currents and frequent large swells, the islets lack any terrestrial flora or fauna. The only structure is the lighthouse, finally built in 1948. The Banks are the location of numerous ship wrecks, the most recent being that of the Greek cargo ship Olympia that ran aground and wrecked on 16 June 1921. The oldest known wreck is that of the San Medel y Celedon that ran aground and was lost during a major storm in 1591.
Since 4 April 1988 the Formigas Banks, which encompasses the Formigas Islets and the neighboring Dollabarat Reef to the southeast, have had the status of Nature Reserve and is protected by decree. The Formigas Bank is essentially a submarine volcano where the cone is delineated by the Formigas Islets of the northwest and the Dollarbat Reef to the southeast. In the ancient submerged crater there is a great diversity of marine species common to the Azores. The abundance and diversity of marine life were noted as early the 16th century. Among the species typically seen are wrasse, sergeant fish, grouper, parrotfish and the Atlantic goliath grouper.