If the day has energy left and the weather is clear, consider the drive south toward the Picos de Europa foothills and the entrance to the Cares Gorge.

The Cares Gorge is a trail cut into the rock face of a river canyon — twelve kilometers one way, carved by engineers building a water channel in the 1920s, now one of the most dramatic walking routes in Spain. The path runs along the cliff face above the river, sometimes through tunnels blasted into the rock, with the gorge dropping away below and the limestone peaks of the Picos rising above.

This is not a full Picos de Europa itinerary. The Picos deserve their own trip — their own save file entirely. But the Cares Gorge is a single trail with a clear start and end point and it delivers the mountain experience of the interior in a way that requires no mountaineering and no specialist knowledge.

The full trail is twenty-four kilometers return and takes five to six hours at a comfortable pace. If that is too much on a day that already has coast in it, drive to the entrance at Poncebos, walk an hour in and an hour back, and get a sense of the scale without committing to the full route.

Practical note: the trailhead at Caín — the other end of the gorge — requires a drive through the Liébana valley from the Cantabrian side. From Gijón, enter from Poncebos in Asturias. The road into the gorge entrance is narrow and the parking fills early in summer. Go early or consider it an early morning add-on to Day 5 before heading east.