Torre de São Lourenço or Tower of Saint Lawrence, is a stone staircase, protected by battlements, that goes half-way down the hill. This armored corridor leads to a fortified tower, located about 60 meters outside the Citadel’s wall.
Such structures were quite common in Moorish and medieval castles, as they protected places which were important and vulnerable to attacks, such as wells, outer defensive positions, or watch towers.