Chestnut forests, fast-flowing rivers, Limousin bocage, Périgord valleys, limestone plateaus, the Périgord-Limousin Regional Natural Park offers a mosaic of surprising landscapes. We meet passionate naturalists, craftsmen with ancestral know-how but also scientists, who find here something to quench their thirst for knowledge. We begin our escapades in the company of Frederic Dupuy and Meriem Grégori, from the PNR for a strange expedition in the glacial waters of the Dronne, a 200 km river renowned for the quality and diversity of its biotopes. Thanks to the aquascopes, we are looking for an endangered species: the pearl mussel. The Dronne is one of the rare rivers in France where we still find populations of this freshwater mussel which has the particularity of statistically producing a pearl every 1000 individuals. To better understand the challenges of the European reintroduction program for this species, we meet Magali Baudrimont, an ecotoxicologist at the University of Bordeaux, at the Firbeix fish farm. An opportunity to discover the symbiosis, the strange reproduction process of this mussel. We then set off to meet the last basket makers of Limousin. Nicolas Raffier is the 5th generation of leaf makers. After cutting young chestnut trees with him, we discover the precise gestures and know-how of this family specializing in the manufacture of chestnut chairs and tables. Head north of the Natural Park to reach Rochechouart. A medieval town renowned for its magnificent castle with its inner courtyard and its elegant Renaissance gallery. But for several years now, the beautiful building has not only interested historians. Some of the stones with which the castle was built have particularities that intrigue geologists… Pierre Poupart, curator of the Rochechouart nature reserve, explains to us that these rocks are partly of extraterrestrial origin! They were born from the impact of a meteorite on the site 200 million years ago. Before working for NASA, among others, Philippe Lambert, an astrogeologist, came to study this area in the 1970s. Convinced that Rochechouart was an exceptional site for scientists, he moved heaven and earth to launch a major European research program. Thanks to these drillings, we can study rocks taken up to 150 meters deep… We end our walk at the Moulin de Lapeyre, a few kilometers from Nontron. Here again we are talking about the past, a much less distant past but which could also disappear. Agricultural decline, rural exodus, as in all our countryside, lifestyles have changed more in recent decades than in centuries. Because he refuses to let his country become amnesiac, François Devige has given himself a mission: to gather in one place the testimonies of the know-how, practices, and "genius" that our ancestors could demonstrate... #capsudouest All the news in Nouvelle-Aquitaine ► http://france3-regions.francetvinfo.f... Join our Facebook community ► / france3aquitaine ► / france3limousin ► / france3poitoucharentes Follow us on Twitter ► / f3aquitaine ► / f3limousin ► / f3poitouchtes Download the France 3 Régions application ► http://bit.ly/1FPo7Ga Subscribe to our newsletter ► http://france3-regions.francetvinfo.f...