Fortress of Our Lady of the Assumption, Military fortress in Fortaleza, Brazil

The Fortress of Our Lady of the Assumption is a square fort with 90-metre sides, designed by engineer António José da Silva Paulet, with bastions at the corners named Nossa Senhora da Assunção, São José, Dom João and Príncipe da Beira. Its walls enclose a central courtyard, and a commemorative Latin plaque was placed on the outer north wall at its inauguration.

The first fort on the site was São Sebastião, built at the request of Martim Soares Moreno and soon demolished for its weak structure. The Dutch erected Fort Schoonenborch in 1649; after the Portuguese retook Ceará, the governor Manuel Inácio de Sampaio e Pina Freire laid the cornerstone of the present fort on 12 October 1812, honouring the birthday of Prince Pedro de Alcântara. Its square plan with four corner bastions was drawn by Lieutenant-Colonel António José da Silva Paulet, and works were completed on 17 August 1822.

The fort is still the headquarters of the Brazilian Army's 10th Military Region, a role it has held since 1958. Guided tours led by a soldier cover the parade ground, the chapel and the cell where Bárbara de Alencar, held locally as Brazil's first female political prisoner, was detained in 1817. The Museum and Pantheon of General Sampaio and a statue of Martim Soares Moreno are also on site.

The fort stands on the Marajaitiba hill above the left bank of the Pajeú stream. Visits require prior scheduling with the Social Communication office of the 10th Military Region, and a soldier accompanies the group through the parade ground, Bárbara de Alencar's cell and the chapel.

The fortress gave the entire city its name and was the center around which Fortaleza developed as an urban area. Many residents today may not realize their city was named after this military structure that served as the origin point for urban growth.