Santillana del mar is nice (but dont be tempted to stay the night, it’s dead when the tourists go).
Barcena Mayor is a nice little place, with some good walking nearby (think you can walk to Cabezon del sal).
Potes is a good base with nice bars and restaurants.
Covadonga is a pleasant place to visit, impressive church.
Cangas de Onis is another nice town to wander around.
Basically, most of the villages/towns a re worth a stop. Small cheese makers, nice old buildings etc..
Decent maps are easy to get.
Should be there now, but ill. Grrrrrr.