This fortified monastery of the Maltese order was built in 1356 by the priest Alvaro Gonçalves Pereira, father of Nuno Alvares Pereira who defeated the Castilians at Aljubarrota. It is a compact and fortified complex, whose high walls are topped with crenellations. The church has been the focus of a truly marvellous piece of restoration. Note the simple lines and sheer height of the nave. In the centre, the robust but elegant architecture of the small floral cloister is particularly eye-catching.