Old Town (Old Town Walk)

Mértola is often called a museum town, and the label is earned. It stands on a ridge above the point where the Oeiras stream meets the Guadiana, in the Baixo Alentejo, and its history is visible in layers: Roman, Islamic, and Christian. The Romans knew it as Myrtilis and used it as a river port, because the Guadiana is navigable up to this point from the sea. That trade brought wealth, and the town kept its role through the Islamic period, when it was the capital of a small kingdom for a time in the 11th century.

A walk around the old town takes in the main points in a short space. At the top of the ridge stands the castle, begun in the 13th century after the Christian conquest and later strengthened, with a keep that gives a wide view over the river, the whitewashed roofs, and the hills. Just below it is the parish church, the Igreja Matriz, which began life as a mosque in the 12th century. Its arched doorways, small domed forms, and prayer niche show its origins, and it is one of the few mosques in Portugal to have survived, converted to a church after the reconquest.

The town's museum project is spread across the streets. A Roman house and the remains of a Roman forum with its cryptoporticus can be seen, a museum of Islamic art holds ceramics and everyday objects from the period, and the town's early Christian remains are also displayed. The Roman and Islamic traces can also be seen on the riverside, where a tower and walls descend toward the water and once protected the port.

The streets are narrow and steep, with whitewashed houses with blue or yellow edges, small craft shops selling woven rugs and pottery, and cafés where you can sample local dishes. Mértola sits in the Guadiana Valley Natural Park, and the landscape beyond the town is dry, empty, and beautiful, with birdlife and river views.

The town is best explored on foot, wearing comfortable shoes, and it suits history readers, photographers, and travellers who like quiet, out-of-the-way places. A visit takes half a day, and an overnight stay gives a calm evening by the river.