This hut (at 2026 m. of altitude) is slightly isolated from the itineraries frequently followed by hikers: for this reason, it is recommended for those who, in mountain, prefers a bit of solitude as opposed to more crowded places.
From the hut, in addition to the classical climb to mount Aga (in the bargain, very beautiful and achievable with same-day return), you can climb down to d’Ambria valley in Valtellina and access to more challenging mountains of this area, or reach Mambretti hut in the valley di Scais.
Longo hut, built by CAI Bergamo in 1923, was initially dedicated to Calvi brothers and only after to Longo brothers.
Because of the war, the small building underwent a gradual degradation that persuaded the section to erect another one, in the immediate vicinity of Lake Rotondo.
At the beginning of the fifties, the Alpine Society of Scais Bergamo demanded and achieved by CAI the management of the small hut. Once completed the reconstruction, it was dub to the memory of Giuseppe and Innocente Longo brothers, tragically perished in August 1934 on Mount Cervino. In the years that followed, the hut got down to attract an ever increasing number of mountain climbers, involving the need of a further closure to execute some improvements on old equipment.
In 1985, the Society considered worthwhile to proceed with a global expansion of the premises, enlarging the dining room and increasing the number of beds; lastly, in 1999 further  extension work have been completed.