In the past, watermills used the Guadiana River to transform grain into flour. Today, watermills are places of leisure.

A mining complex established in the 19th century to exploit a copper-bearing pyrite mine whose deposit had been exploited in Roman and pre-Roman times. The main elements extracted during modern mining, between 1854 and 1966, were copper and sulfur. After the mine's closure, the equipment was dismantled and sold, leaving the landscape today marked by mining activity and acid drainage.

The canals on the Guadiana River were used to capture fish. The last traps of this type are in the municipality of Mértola, which have been discontinued, diverting fish to easier-to-catch locations.

The Clock Tower was likely built in the late 16th or early 17th century, as part of the reorganization of the Praça do Município urban area. This building was erected near a group of buildings representing political, administrative, judicial, and economic power. Reusing an old city wall tower, it began to mark the boundary of Praça do Município and became one of Mértola's emblematic elements. In 1896, the original clock was replaced by a more recent one that continues to keep time in Vila Velha to this day.

A castle of Romanesque and Gothic architecture, with quadrangular towers. The keep stands on the steepest slope. Of the medieval gates, only the Misericórdia Gate, overlooking the Guadiana River, remains. The old citadel, as well as important sections of the wall that enclosed the town, remain. Archaeological work in the castle's citadel has uncovered a Moorish quarter from the 12th and 13th centuries and several Roman structures from the 4th century. The Arab ceramics found are on display in the Mértola museum.

On the northern slope of the Castle Hill, the possible Roman city forum creates an artificial platform, supporting the imposing monumental complex of the city of Myrtilis. This entire platform, leaning against the wall, rested on a solid underground gallery approximately 30 meters long and 6 meters high. In Late Antiquity, in the 5th and 6th centuries, lavish religious buildings were erected here; among them, a possible Episcopal Palace and a baptistery, of which significant fragments of a beautiful set of polychrome mosaics remain. During the Islamic period, during the 12th and 13th centuries, this entire area was occupied by …

On a steeply sloping area below the castle lies the old mosque, converted into a Christian church in the 13th century, with a Manueline-Mudejar façade featuring battlements and spires. It is the only one that still retains the volume and some decorative elements of the Arab temple that preceded it, notably the "T" layout, the presence of the mihrab and the compartment in the "qibla" (mosque wall) facing Mecca, the existence of five naves from the old mosque, the statuary, doors, and remains of the mihrab.

In this church the highlight goes to the drawing and grandeur of the main portal.

Temple with diverse influences on style and architecture as the Gothic, Manueline, Mannerist and Baroque. In the Baroque, for example, are the main altarpiece and the painting of the chancel, as well as the pulpit.

Church with three naves, which presents, inside, gilded and polychrome altarpieces. The main altarpiece has mural and Dome decorated by 19th century murals.