The ancient walled-in town of Mértola is on a hill overlooking the Guadiana River. At its center is the Praça Luís de Camões, a charming square lined with citrus trees. The town hall sits on the square's western end, with the Torre do Relógio, an impressive clock tower built in the late 16th century, on the opposite side.
Mértola has seen several archaeological excavations in recent years. The artifacts from these digs are all part of the Museu Arqueológico (Archaeology Museum), which has branches—each with displays from different periods—in several locations around town.