In Osteno there’s a canyon, unfortunately it’s unknown to the most as it has been inaccessible to the public for some decades. Anyway it didn’t use to be like that: on late 800s and during the firsts decades of the 900s this Canyon used to be a very attractive tourism pace. There was a boat from Lugano taking people to Osteno, to allow the sightseeing of the canyon. At the entry there was a typical restaurant named “crotto”: the fresh breeze coming from the canyon gave a relief during the hot summer days.  The only one way to visit the canyon was using a special double-prow boat as there was no way to make a u-turn once inside the canyon’s corridor made by narrow rock walls.
Inside the canyon there’s a huge rock where the waterfalls created by the rivers Telo and Lirone fall: this place is called the room of the throne. In this room during summertime the sunshine going trough the wall of water of the waterfalls creates small rainbows all around.
The Orrido is just at the entry of the town. The writer Antonio Fogazzaro quoted this canyon in his work “Malombra”. Some shots from the movie by Mario Soldati (1940) where taken inside the canyon.

WARNING FOR RAFTERS!
Don’t raft the rivers from above as once in the orrido there’s no way to back or forward.