The Campo Valdés baths are the most significant Roman remains in Asturias, preserved beneath a glass shelter at the base of the Cimadevilla headland. The complex was built in the first century AD and served the Roman settlement of Gigia for several centuries; what survives includes the floor plan of all the main rooms, sections of original mosaic, and the hypocaust pillars that carried the underfloor heating. The interpretation is clear and thoughtful, with models and explanatory panels that place the baths within the wider context of Roman Asturias.
The site is compact — you can see everything in 30–45 minutes — but it has a particular quality that comes from being right at the edge of the old town, with the sea just beyond and the medieval fishermen's quarter immediately above on the headland. The continuity of occupation is tangible here: Roman, medieval, modern, one on top of another at the same geographical point. The museum is partially open-air (the ruins are exposed to the sky through the glass roof) and has a very small entrance fee. It combines naturally with a walk up through Cimadevilla to the Chillida sculpture and then back down through the cider bar streets on the other side.