A small 9th-century fountain structure just north of the old town, built to channel a natural spring. It looks modest — a stone canopy over a basin — but it holds UNESCO World Heritage status as the sole surviving example of pre-Romanesque civil hydraulic engineering in Europe. The carved cross and Latin inscription above the arch tie it directly to the Asturian royal building programme that produced the Naranco churches.
La Foncalada was rediscovered and excavated in the 20th century after being buried and built over for centuries. It sits in a small sunken garden at street level, easy to miss if you are not looking for it. Worth a brief stop on the way between the cathedral and the Naranco churches.