Hospital de Sang

Hospital de Sang is a natural rock fissure hidden in the woods above Mura, deep within the Sant Llorenç de Munt i l'Obac Natural Park. Despite the name, it isn't a building at all — it's a geological formation, a narrow rock passage that once served as a makeshift field hospital nearly two centuries ago.

What exactly is this place?

Hospital de Sang sits on the slope of the Cort Fosca ridge, part of the Serra de l'Obac range. It's a residual rock conduit roughly 20 metres long, open at both ends like a tunnel, with a triangular cross-section reaching about 5 metres in width and 7 metres in height. Remnants of dry-stone walls still stand inside, once used to close off sections of the passage and turn it into a sheltered space.

The name refers to events from the 19th century Carlist Wars, when this crevice was used as a point of care for wounded soldiers. The choice of location wasn't random: the spacious interior offered protection from both weather and enemy sight, while the nearby Cort Fosca cave held a water source, the Font Fosca spring, essential for treating the injured.

How do you get there?

Hospital de Sang is reached via hiking trails starting from Mura and running through the natural park. Many routes combine it with the nearby Turó de la Cort Fosca viewpoint, letting you plan a circular walk that takes in both sites in a single outing. The paths cross terrain typical of the Serra de l'Obac — limestone outcrops, scrubland, and small caves — so sturdy hiking boots are a good idea.

By car, the most practical approach is to drive to Mura or one of the park's access parking areas and continue on foot from there. The walk itself isn't long, but it does cross uneven, rocky ground.

What will you see on site?

The fissure itself is striking simply for its shape — a narrow, tall tunnel cut through solid rock, with surviving traces of the stone walls that once divided and sheltered its interior. The site combines natural interest, as a rock formation typical of the karstic Obac terrain, with historical weight as a relic of a 19th-century conflict. The surrounding dense forest and rocky slopes give it a raw, unpolished character, far removed from any built-up tourist infrastructure.

When should you visit?

Spring and autumn are the best seasons, offering comfortable temperatures for longer walks and the most attractive vegetation around the fissure. Summer heat in this part of Catalonia can make the exposed, rocky stretches of the trail tough going, so an early morning start is advisable.

Frequently asked questions

Is Hospital de Sang an actual building? No — it's a natural rock fissure and tunnel. The name refers to its historical role as a field hospital, not to any architecture.

Where does the name come from? From the 19th-century Carlist Wars, when wounded soldiers were treated inside this rock shelter.

Can it be combined with another nearby attraction? Yes, popular routes link Hospital de Sang with the nearby Turó de la Cort Fosca viewpoint as part of a single circular hike.

Is the trail difficult? The stretch itself is short, but it crosses uneven, rocky terrain typical of the Sant Llorenç de Munt i l'Obac park — sturdy hiking footwear is recommended.