The Sardona Unesco World Heritage information board sheds light on this geological phenomenon: 250 million-year-old verrucano rock muscled its way through 35 to 50 million year-old Flysch to form the Alps.
From Chur by bus to Flims, chairlift to Foppa and on to Alp Naraus, then on foot via hiking trails to the Cassons.
View: Over the Ringelspitz, Piz Segnas and Tschingelhörner including the Martinsloch (from the highland path), Surselva and Lumnezia, into Domleschg and as far as Bernina on a clear day
Attractions: Cassons – Tschingelhörner – Alp Nagens highland trail, Romansh trail from Foppa (chairlift) to Scheia and Fidaz
Overnight stays: No
Winter: Winter sports region LAAX (Destination Flims Laax Falera)
Special comments: Historic Pinut via ferrata to the Cassonsgrat (1907 and 2007 entirely renewed)