some short info(aka Val di Tartano) this is the 3rd valley (starting from west) that enters the N side (Valtellina)of Orobie ridge.
Made of 2 valleys : Val Corta and Val Lunga (short and long valleys) this valley is well known for its ski-mountaneering trips and for the fine (in spring and autumn) hikes.
The "entrance" is on the Valtellina road between Ardenno and Talamona : follow signs for Tartano, once at the main built up area you can choose between the Val Corta (to the right, only on foot) or the Val Lunga (to the left, you can drive for some more km)
The most known routes here are :
ski-mountaneering : the Cima di Lemma (2348m)
hiking : the Laghi (lakes) di Porcile