Sistema del Trave

Sistema del Trave is a cave system in Cabrales, deep in the central massif of the Picos de Europa in Asturias. It is the deepest known cave in Spain and one of the six deepest on the planet — a magnet for speleologists from across Europe, though for the average visitor it's more of a scenic mountain landmark than an underground excursion.

What exactly is it?

Sistema del Trave isn't a single cavern but the union of three separate karst shafts, each with its own independent entrance high in the central massif of the Picos de Europa: Torca de la Laureola (entrance at 2,042 m), Torca del Alba (1,975 m), and Sima del Trave (1,917 m). The French caving club Spéléo Club de la Seine first discovered the system in 1982, and cavers succeeded in linking all three shafts into one continuous system in 1987. Two years later, in 1989, exploration reached the terminal siphon at a depth of 1,441 m. The full system now totals more than 9 km of passages with a vertical range of 1,441 metres, ranking it among the most notable deep-cave systems anywhere in the world. Its lower reaches carry an underground river — the main collector gallery that gathers water from several smaller streams cutting through the rock.

How do you get there?

The entrances sit high in the mountains of the central Picos de Europa massif, within the municipality of Cabrales, and reaching them means a multi-hour approach on mountain trails — there is no road leading up to the shaft openings themselves. Sotres is the usual starting point on the Asturian side of the range, from where paths climb through high pastures and rocky ridgelines. The terrain is genuinely alpine: rocky, exposed to the weather, and best attempted with solid navigation skills and mountain experience.

What will you actually see?

From the surface, visitors can only reach the mouths of the shafts — dark, deep fissures in the rock set within the classic high-mountain scenery of the Picos de Europa: limestone peaks, glacial cirques, and sweeping views across the massif. The interior of the system itself — the vertical shafts, passages, and underground river — is accessible only to experienced cavers equipped for technical rope descents. The site is legally protected as a Natural Monument (Monumento Natural), a status meant to keep this exceptional karst system intact.

When should you go?

The best window for reaching the area around the entrances is summer into early autumn (June–September), once the high mountain trails are clear of snow and safe to walk. In winter and early spring the approach is often buried under snow and may require winter mountaineering gear. For cavers planning an actual descent, water levels inside the collector gallery matter too — they rise sharply after heavy rain.

Frequently asked questions

Can you visit Sistema del Trave without caving experience? No. Descending into the system requires technical vertical-caving equipment and rope skills. Visitors without that training can only reach the surface entrances and take in the surrounding landscape.

What makes Sistema del Trave different from other caves in the Picos de Europa? It's the union of three independent shafts into a single system reaching 1,441 m deep, making it the deepest cave in Spain and one of the deepest in the world. The full connection between the three shafts wasn't achieved until the 1980s.

How long does it take to reach the entrances? Depending on the route and starting point, the hike from around Sotres to the high-altitude entrances typically takes several hours on mountain terrain.

Does water flow through Sistema del Trave? Yes. The lower part of the system holds an underground river — the main collector gallery — fed by several side streams that cut through the massif.