The urban layout of Ribadesella is characterised by a bridge that divides the fishing port in two. This bridge, every first Saturday of August, is the finish line of the most representative festival of Asturias, the canoe descent of the Sella River. Its historic quarter is declared Property of Cultural Interest.

The historic town of Ribadesella was founded by King Alfonso X (“the Wise”) in the 13th century. It offers visitors an interesting mix of mediaeval town and modernist architecture. The locality has two clearly distinct parts: The east side, in which the old zone of the city lies, and the west side, where an excellent beach and the Tito Bustillo cave, one of the treasures of European cave art, are located.

Similar to the one in Altamira, the stalactites of the cave are more impressive than the paintings. Entrance is limited to 375 visitors per day and so, in summer, it is advisable to arrive early in the morning to enter. It also has a museum of the prehistoric findings of the area.

In the historic quarter, the Santa Maria de Junco and San Esteban de Leces Churches, of Romanesque origin; the Santa Ana Gothic Chapel (15th century) and the Renaissance Chapel of Nuestra Señora de Guía (16th century) are notable. Of particular note as civil architecture is the Town Hall, which is Renaissance and Plateresque, as well as the numerous stately homes dating to the 17th-18th centuries.

Between the end of the 19th century and the start of the 20th, a notable number of romantic villas in modernist and eclectic style were built in the modern district of Arenal de Santa Marina. Among them is the modernist Villa Rosario, built by members of the rich bourgeoisie who had made their fortunes in the Americas.