Level of difficulty: easy
The hike starts and finishes at the Sanctuary of Our Lady of the Desert. This uninhabited place was known as Deserto; there was only a building for chestnut drying, with a XVII century fresco of the Virgin with the Child, known as Madonna delle tre fonti because of the three springs nearby. Chestnut gatherers, wood cutters and coal makers were devoted to this Madonna, and tradition had attributed several miracles to the sacred painting, thus leading to the building of the Sanctuary. In front of the Sanctuary, a short flight of stairs leads down to the gates of the Garbazzo cave (the name comes from the dialect term for a large hole); hence the other common name of Madonna del Garbazzo.
Take the level dirt road that leads across the mixed wood and around Bric Mongarda, to the opposite side of the ridge along Valle dei Tre Re. Turn right before the stream: you will shortly reach Tana dell'Arma. Information boards illustrate the peculiarities of this cave and underground water circulation. Going back a few metres, take the path that goes uphill to Tana dell'Armetta, a cave from which grindstones used to be extracted. From this point you may go back on the same road, or go further along the loop, which becomes more demanding. A steep uphill path leads across the wood to a crossroads: go right downhill on a forest road as far as a stream; there, a path begins that leads back to the sanctuary. Along the descent you will notice an ancient drying house, testifying to the valley's prevalent activity in the past.