It was the first convent to be built in the lands conquered from the Arabs and is located outside the belt of walls and in front of the main gates of the city, the Portas de Mértola.

Founded in 1268, it was secularized in 1852 and shortly afterwards adapted to a barracks, which led to the destruction of the Capela dos Ossos, identical to the one in Évora.

The façade is made up of 3 large walled-up arches that communicate with a large patio that precedes the convent church. The portico of the church, in the mannerist style, has the symbol of the Franciscans on the pediment. The cloister opens to the side, consisting of 4 galleries and an uncovered patio with a cistern in the center. These galleries date back to the 16th and 17th centuries.