Like the Tower of Belém and the Monastery of the Hieronymites in Lisbon, and Goa in India, Angra do Heroismo is directly and tangibly associated with an event of a universal historic significance: the maritime exploration that allowed exchanges between the world's great civilizations. Set in the mid-Atlantic, the port of Angra, obligatory port-of-call for fleets from Africa and the Indies, is the eminent example of a creation linked to the maritime world, within the framework of the great explorations.
Within the history of the maritime explorations of the 15th and 16th centuries, which established communications between the great civilizations of Africa, Asia, America and Europe, Angra do Heroismo holds an eminent position: this port on the island of Terceira, in the Azores, served as a link for almost three centuries between Europe and the 'New World'. Vasco de Gama in 1499 and Pedro de Alvarado in 1536 set up an obligatory port-of-call for the fleets of Equatorial Africa and of the East and West Indies during their voyages back and forth from Europe. A Provedoria das Armadas e Naus da India (Office of Fleets and Vessels of the Indies) was immediately set up there.
The site, admirably chosen by the first navigators, was protected from the prevailing winds by a series of hills; the port comprises two natural basins, that of the Beacon and that of the Anchorage (Angra) from which the village took its name. An impregnable defensive system was installed immediately following its foundation with the construction of the large fortresses of São Sebastião and São Filipe (today named São João Baptista). At the same time, it was decided to set out the city based on an original layout: the characteristic chequerboard plan of new cities was altered to take into account the prevailing winds.
Angra do Heroism thus offers a perhaps unique example of the adaptation of an urban model to particular climatic conditions. It has been conjectured, and not without reason, that the choice was imposed by the navigators and their cartographers. Angra was officially raised to the status of a city on 21 August 1534; during the same year, it became the seat of the Archbishop of the Azores. This religious function contributed to the development of the monumental character of the city where the cathedral of the Santissimo Salvador, the churches of the Misericórdia and of the Santo Espérito, the convents of the Franciscans and the Jesuits, were all constructed in the Baroque style. Even following the earthquake of 1 January 1980, Angra has preserved the better part of its monumental heritage and a homogenous urban ensemble, characterized by original vernacular architecture.