The Monastery of Santa María de Raíces is part of the Raíces Viejo Historic Ensemble, in the municipality of Castrillón. According to historical sources, this dune landscape by the sea already held a primitive church dedicated to Santa María, first mentioned in the year 905.

Around 1413, a nobleman from Avilés founded a Franciscan hermitage here; in the middle of that century it passed to the Mercedarians, who gave the complex the name Monasterio de Santa María de la Merced. Over time, local residents occupied the buildings and built structures of the old hermitage into new farmhouses, which has allowed much of the oldest monastic fabric to survive. The monastery is included in some of the guided visits that also take in the Castillo de Gauzón and its interpretation centre.