Last month Vitória went to the north of Portugal and visited a few places in the Minho region. One of the places she visited was Caminha, from where she sent me this card with the Ínsua Fort.
Nunes de Almeida Editores: Postais de Portugal
Ínsua Fort was built in the seventeenth century, under the reign of King John IV to defend the Convent of Santa Maria de Ínsua (built by the Franciscan Order in the century XIV), which is in the main square of the fort, and strengthen the defense of the Portuguese coast during the War of Restoration.
Note also that has a well of fresh water, one of only three in the world located in the sea. The fortress can be visited by the public, and the crossing to Ínsua provided by the Captaincy of the Port of Caminha.