Tournemire hiking circuit

This 1885 m long old railway tunnel was excavated towards the end of the 19th century. In 1988, a laboratory designed to undertake, geophysical, geomechanical and hydrochemistry studies was set up inside the tunnel. The aim of this fundamental research, carried out by the Nuclear Safety and Protection Institute, is to gain more knowledge of the way underground water moves and transports dissolved materials. It also examines the geological structure of the area. Some grey marine marl outcrops can be seen in the surroundings and are an equal mixture of clay and limestone.To get more information: IRSN

Dry Grasslands which are iconic features of the caussenard landscape originate from pristine forests that have been transformed by human actions (land clearing, stubble-burning, farming and pasture). This ecosystem is a semi-natural environment with outstanding biological particularities: it provides a critical habitat for rare animal and plant species and is a perfect hunting ground for birds nesting in surrounding cliffs and gorges. Moreover, these traditional pastoral lands have been used for centuries. At the end of the spring season, the causses scenery is decked out with tall grass (feather grass) that forms the shape of a thick silver hair. (source PNR Grands Causses).

Ever since the Neolithic period, humans have kept on improving the numerous natural ponds that they came across all around the Causse. They took advantage of these small land depressions called sotch or doline that provided essential water supplies to ensure the sheep watering, but were also used as laundry places or fish ponds, although their clayey bottom have always posed problems with leakage.In the Occitan language, the word lavanha refers to all kinds of ponds whether natural or hand built, whereas at the PNRGC, we have chosen to keep the word lavogne, or lavagne to designate ponds with paved bottoms, for they have witnessed the development of pastoralism over the 19th century. (source PNR Grands Causses).

Situated in the southwest of the Larzac Causse, the Tournemire Cirque is a remarkable geological area marking the bondary beetwen the fore-causses and the great causses. It presents limestone ledges and rocky escarpments with caves and cavities where raptors such as the eagle owl and the golden eagle nest.

The great Tournemire amphitheatre is one of the most outstanding escarpments of the western edge of the Larzac and as such is classified "Zone Natura 2000". The lower slopes are the only part where Toarcian marls are visible in the SW erosion gullies, everywhere else these marls are hidden under rocky slopes and big rock slides. At the top of the slopes, the dolomitic limestone ruin-shaped cliffs frame the outline of this amphitheatre.

Le Cirque de Tournemire, zone Natura 2000, abrite une riche biodiversité. Les falaises du cirque sont le terrain de nidification et de jeux pour de nombreux oiseaux, des plus expressifs aux plus discrets : Hirondelles des rochers, le Martinet à ventre blanc, le Crave à bec rouge, le Tichodrome échelette, rapaces rupestres dont le Grand Duc d'Europe. On retrouve également d'autres espèces emblématiques, tel que le grand rhinolophe.