In 1762 its fort, the Little Morro, on the N.
One of these, the Morro Velho mine, belonging to an English company, is not only the deepest gold-mine in existence (over 2000 ft.), but it has been worked since 1725, and since 1835 by its present owners.
Some good mines, like Morro Velho and the abandoned Gongo Soco, have been developed in Minas Geraes, but the great majority are small and not very productive.
Alacran is a small islet off the lofty " morro " of Arica.
In the work of improving the city, the national government assumed the expense of the commercial quays, the filling of the Sao Christovao bay, the opening of the Mangue canal and its embellishment, the opening of the Avenida Central, the extension of the sewage system and the addition of new sources to the water supply, while the city was responsible for the Avenida Beira-Mar, the opening of a new avenue from the Largo da Lapa westward to Rua Frei Caneca, the removal of the Morro do Senado, the widening of some streets crossing the Avenida Central and the opening and straightening of other streets.
Of the sea portal stand the Morro, a picturesque fort (built 1633 seq.), on a jutting point 200 ft.
The passage north of Puna Island is known as the Morro channel, but its entrance is obstructed by shoals and it is considered dangerous for shipping.
It lies in the north-east part of the gulf, and is separated from the Ecuadorean mainland by the Morro channel, and from the southern mainland by the wider and deeper Jambeli channel.
Of the harbour entrance; the Castillo de Los Tres Reyes del Morro and San Carlos de la Cabana, to the E.; the Santo Domingo de Atares, at the head of the western arm of the bay, commanding the city and its vicinity; and the Castillo del Principe (1767-1780), situated inland on an eminence to the W.
El Morro, as it is popularly called, was first erected in 1590-1640, and La Punta, a much smaller fort, is of the same period; both were reconstructed after the evacuation of the city by the English in 1763, from which time also date the castles of Principe, Atares and the Cabana.
Its commanding position gained it in 1634, by royal decree, the title of "Llave del Nuevo Mundo y Antemural de las Indias Occidentales" (Key of the New World and Bulwark of the West Indies), in reference to which it bears on its coat of arms a symbolic key and representations of the Morro, Punta and Fuerza.