Really nice section through some great scenery. The later section along side the river and through the tunnels is particularly nice.
Fantastic road bordering Embalse de Sobrón. In the middle
of it you can visit the medieval City of Frias.
In Trespaderne you can choose to go to the medieval town of Medina de Pomar, going north to Bilbao through another fantastic road, or going west to Santander through another panoramic road following Ebro river.