The monastery of the Benedictines is part of the UNESCO heritage site "Late Baroque Towns of the Val di Noto (South-Eastern Sicily)". The monastery is currently the seat of the university of Catania's Humanities studies department, and it can be visited by guided tour only. There is a tour every hour, and it lasts around 90 minutes.
The monastery is huge, and it was originally built during the 12th century. It was expanded several times. After the 1669 Etna eruption and the 1693 earthquake, the monastery was rebuilt as it is today. In 1867 it became part of the state treasury, and it housed barracks, schools and technical institutes, the Civic Museum, an astrophysical observatory and a geodynamics laboratory.
It was damaged by bombings during WW II, and later it was restored and it was assigned to the University of Catania.
The guided tour was very interesting, and covered the history of the monastery, as well as visiting the cloisters, the gardens, the refectory, the underground library, the remains of a Roman villa, the remains of hardened lava of the 1669 eruption, the monumental staircase. I did the tour on a Saturday, so also the Abbot's quarters could be visited (on work days they are offices of the University).