Mértola, that was called Myrtilis by Julio Cesar, rises in a small hill on the right flank of the Guadiana. Today no longer they are left in the river those esturiones that were coined in the Roman currencies, but the city gives glorious faith of its last one with the numerous museums that populate it and that turn it a Villa-Museum. In addition, Mértola is the heart of the Natural Park do Vale do Guadiana, an extension of almost 70,000 hectares that is crossed by the river of north to the south.
In this villa we found museums that remember the passage to us of the Romans, the Arabs and the paleocristianos, but also must enjoy its medieval castle, that is constructed on Islamic structures and from which we enjoyed splendid views.
Nevertheless, building more remarkable of Mértola is Church of Our Lady of Announcement, that in fact is one old mosque built in the century XI, that was transformed into Christian temple in century XIII, but that conserves its structure almohade, mihrab and the wall of quibla.