The perfect starting point is Castello square in Chiavenna, where to take Maurizio Quadrio street and, before reaching the bridge on Mera river, turn right in Poiatengo street. Along this evocative path among the river, woods, and cliffs, reach Prosto di Piuro, where it is worth visiting the several crotti, the church devoted to the Assunta (the Virgin Mary) and a soapstone workshop. From the churchyard on the left, a steep and stepped trail runs through wonderful woods showing the first testimonies of soapstone ancient mining activity: the most ancient quarries, still open-air. Upwards on the rocks smoothed by glaciers there are astonishing prehistoric engravings. Once having reached Passo Capiola (489 m a.s.l.), the descent to Chiavenna offers two routes: the one on the left easier along the small hollow through wonderful clearings, or the one on the right where, climbing up to Sasso Dragone (520 m a.s.l.), it is possible to admire more closely those glacial erosion phenomena that give the name to the natural reserve. The detailed description of the main points of interest can be found in the several panels along the routes.