The path retraces the K15 Terminillo, an important event for trail running enthusiasts which takes place every year along well-marked CAI paths. The excursion has a first section in common with the K42 Italia route, and then goes around, with a suggestive traverse, the north face of Monte Terminillo reaching the Sebastiani Refuge.

We start from Pian de’ Valli, a mountain tourist resort in the central Apennines, descend to the Rifugio La Fossa where it is possible to admire the Sassetelli Ridge and the Valle degli Angeli, and then climb towards the highest source in the Reatini Mountains territory, the Acquasanta Spring. On the way along the summit it is possible to refresh at the Rifugio Sebastiani, named after Angelo Sebastiani, a founding member of the CAI of Rieti, which has always been considered a meeting place for mountain enthusiasts.

The climb to the summit of Monte Terminillo 2217 m is rewarded by the contemplation of the infinite, the view of suggestive landscapes and the beauty of nature. It is the highest peak of the Reatini Mountains, known in ancient times as Monte Gurgure and Mons Tetricus, it is one of the best-known symbols of Sabina, a constant landscape presence along the consular road Salaria, the so-called Salt Road.

The ring ends with a dizzying descent after passing by Rifugio Rinaldi. Bombed in the Second World War and rebuilt by the CAI of Rieti, it is named after Massimo Rinaldi who was bishop of Rieti from 1924 to 1941.