city on the south coast of Terceira, an island of the Portuguese Azores archipelago in the North Atlantic. It lies at the base of Mount Brasil. Angra became a city in 1534. The words do heroísmo commemorate the island's resistance to invading Spaniards in 1580–82. It was the capital of the Azores from 1766 to 1832 and is still the see of the Azorean diocese. Its fortresses include the 17th-century São João Baptista (on Mount Brasil), São Sebastião, and a 17th-century citadel. A major earthquake in 1980 severely damaged many structures on Terceira but left the North Atlantic Treaty Organization (NATO) military air base at Lajes relatively unscathed. The central zone of Angra do Heroísmo was designated a World Heritage site in 1983. Pop. (2001) 14,316.