The best starting point for hikes into the mountains from the Picos’ eastern side has to be Espinama, though if you’re at all pressed for time, taking the cable car up from Fuente Dé and then hiking back down to Espinama (10km; 3–4hr) makes a quick and relatively pain-free alternative.
A superb trek (12.5km; 5hr) follows a dirt track (also passable in 4WD vehicles) from Espinama to the village of Sotres, 8km east of Poncebos. Setting off north from Espinama beneath an arching balcony alongside the Peña Vieja bar, the track climbs stiffly, winding past hand-cut hay fields and through groups of barns, until tall cliffs rise on either side to form a natural gateway. Through this you enter a different landscape of rocky summer pasture and small streams. As you near the highest point, 4.5km or perhaps two hours along, the track divides at a small barn; the left-hand path leads up to the Refugio de Aliva and the top of the cable car, but for Sotres you should continue straight ahead, past a chapel (visible from the junction), up to the ridge forming the pass.
Over the divide the scenery changes again, into a mass of crumbling limestone. In spring and winter, the downhill stretch of track here is slippery and treacherous to all but goats. From the foot of the hill, where a seasonal bar sells drinks, you’ll have to climb slightly once again to the east to reach Sotres itself, which, when it appears, has a grim, almost fortified feel, clinging to a cliff edge above a stark green valley. Alternatively, a zigzag climb to the west marks the start of the 5km route (around 2hr) to the more appealing village of Bulnes.