The Abbey of Casamari was built by some monks from Veroli in 1036, along with the Abbey of Fossanova, where St. Thomas Aquinas died in 1274. It is a masterpiece of Gothic-Cistercian architecture in Italy.

The beautiful Cloister is framed by a series of twin columns leading to several buildings, the main one being the Church which has the form of a basilica with a nave and two side aisles.  It has a wonderful choir and, of particular interest, the Capitular Hall.

Beautiful are the non-religious areas, too: the Museum, rich in archaeological remains from the Roman era and works of art, the Refectory and the Library, with its ancient volumes, parchments and incunabula.