Sentier karstique de Saint-Paul

Useful Information

Location: Relais du Bois Perché, 31160 Aspet.
A64 exit 18 St. Gaudens, D33R D921 to La Vielle, across the bridge, D5 south to Aspet. At Aspet turn first left, follow signs to Le Bois Perché.
(43.024736, 0.795140)
Open: no restrictions.
Fee: free.
Classification: TopicSentier Karstique KarstKarst
Light: bring torch.
Guided tours: self guided, L=4.6 km, VR=200 m, D=1.5 h.
Photography: allowed
Accessibility: no
Address: Sentier karstique de Saint-Paul, Relais du Bois Perché, 31160 Aspet, Tel: +33-561-94-86-51. E-mail:
Lucienne Weber, Comité Haute-Garonne Speleology and Canyon Department (CDSC 31). E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


26-APR-2014 karst trail inaugurated.


The Sentier karstique de Saint-Paul (Saint-Paul Karst Trail) starts behind the restaurant Le Bois Perché, just follow the road Las Vignes to the end. From the starting point follow the road to the Campagne farm, then take the trail on the left along the dry valley. There are some interesting rock formations and shallow solution dolines. Finally, you will reach a picknick are with tables and benches and the Chapelle Saint-Paul, after which the trail was named. A short detour will bring you to the karst spring below the chapel. Back on the trail you will ascend in the forest Bois Perché and walk along the ridge. The Trou Souffleur is a collapse doline with vertical walls. A trail on the left side will bring you to the Grotte de Terreblanque which has a spectacular karstfenster. Now the trail leads downhill to the starting point. The trail is easy and only a good hour walking time, with very moderate ascends. With some time to explore the cave and other stops it will take about 1.5 hours.

The trail gives a complete overview of the variety of karstic landscapes, their formation and their uses by man. At the resurgence of Saint-Paul the legends around the spring are explained. That's why the trail is also called Les mystères et racontars d'une résurgence (The mysteries and gossip of a resurgence).

Some time ago the occurrence of Radon in caves and other underground structures was discussed. The gas is not poisonous and quite harmless, but there is a small percentage of radioactive isotopes naturally occuring. There were some discussions how dangerous the radioactivity actually is, but after some heated discussions it became clear that it is actually quite harmless. Only people who work underground and spend their full working hours underground have a small problem. On the other hand the exposition to radiation is even in this case below the natural radiation in mountain areas. However, the explanatory signs try to explain the extent of the danger in an unexcited and objective manner. We guess driving down the Rhone valley freeway along the numerous atomic power plants is by far more dangerous than visiting a cave.

A booklet for the karst trail is available at the Bois Perché reception or at the Aspet inter-municipal tourist office for 5 €. There are numerous websites which offer the route data for download. This is actually not necessary as it is well signposted. Like any hike we recommend goof walking shoes, sun protection, some drinking water and a raincoat in case of rain. Also, a lamp for the cave is a good idea. On certain days the local cavers organize guided walks for a small fee.

The Cave of Saint-Paul at the resurgence is not accessible it requires caving gear. It is horizontal and requires no climbing, nevertheless helmet, headlamp, overall and gloves are strongly recommended. The local tourist office offers cave trekking trips into this cave. They can be booked online on their website. Participants get detailed information what equipment they should bring.