Northern Picos and the weather is gorgeous. Following Route 3 - Ocean and Mountain from Back Roads Spain

Walk in the Cares Gorge was a highlight. It's a 25km trek, there and back, between Poncebos and Cain. It's spectacular, steep at the start and the end, but flat for the most part. The route follows a canal that takes water down from Cain to a hydro station at Poncebos and the track was constructed to provide access for both building the canal and maintaining it. 

Another walk was from Poncebos up to Bunes. There's no road only a funicular railway. We walked up to Bunes and took the train back down

A day walking in the Sierra de Covadonga. Park in Covadonga then take a coach to the visitors centre and the start of various walks