Follow the jade-green Lobos River through one of Castilla y León's most dramatic gorges. The canyon walls — carved through pale Jurassic limestone — rise over 100 metres above you, riddled with caves and crowned by griffon vultures riding thermals. The unmissable highlight is the Ermita de San Bartolomé, a solitary Templar chapel embedded in the rock, reachable with barely any effort from the Valdecea car park.

The trail is fully signposted starting from Ucero on the SO-920 road and passes through fragrant pine-and-juniper woodland. Birdwatchers should pack binoculars — the park hosts one of the largest griffon vulture colonies in the Iberian interior.

The result of 140 million years of erosion, the Duratón gorge is geology as pure theatre. Cliffs plunge over 100 metres straight into the turquoise river, and the air is thick with the sound of vultures wheeling overhead. The Senda Corta is the best introduction — a short, varied trail that captures the gorge's most spectacular stretch without requiring a full day's commitment.

Along the way you'll pass the partially ruined Monasterio de la Hoz, a medieval monastery tucked into a cliff ledge, and several viewpoints where the canyon bends make for some of the most photogenic scenery in inland Spain. The recommended seasons are autumn and spring, when the light is golden and crowds are thinner.

Nothing prepares you for your first sight of Las Médulas. What look like alien rock towers — a landscape of fire-red stone needles and hollow hillsides — are in fact the ruins of the Roman Empire's largest open-cast gold mine, worked from the 1st to 4th century AD. The sheer scale is humbling: 2,000 years of erosion and centuries of human extraction have sculpted an entirely surreal world.

The Ruta de las Miradas connects the three key viewpoints — Orellán, Las Médulas village, and Lago de Carucedo — following an easy trail through chestnut groves and past the dark mouths of Roman mining galleries you can explore on foot. This is the route recommended by the Junta de Castilla y León's official park leaflets.

Lago de Sanabria is the largest natural glacial lake in the Iberian Peninsula and the centrepiece of one of Castilla y León's most beloved natural parks. The circular route (marked with navy-blue trail markers, Senda Nº 1) loops the entire lake through oak and birch woodland, along cobbled old paths, and past the medieval village of San Martín de Castañeda with its lakeside monastery.

The scenery shifts dramatically as you circle: dense glacial valleys give way to open moorland, then drop back to the lakeshore with its crystalline water and sandy beaches. Wildflowers carpet the trail in spring; in autumn, the birchwood blazes gold. This route is best enjoyed as a full day out with a packed lunch — there are no services on the trail itself.

Hidden in the Montaña Palentina — a mountain range so beautiful locals call it the Beautiful Unknown — the Tejeda de Tosande is one of Spain's most impressive yew tree forests. Ancient yew trees (Taxus baccata), some centuries old, twist and darken the path like something from a fairy tale. The route follows an interpretive trail with information boards managed under the Junta de Castilla y León's Natural Spaces Network.

This is an ideal route for families, autumn leaf-peepers, and anyone who wants big atmosphere with moderate effort. The village of Cervera de Pisuerga nearby makes a lovely lunch stop and is one of the region's most charming mountain towns.