The Museum is named Gaius Maecenas Cilnio and has as seat the former monastery of St. Bernard, valuable building that stands on the ruins of a Roman amphitheater (mid-second century AD) whose vaults are visible on the first floor. The Museum opened in 1823 as a collection of "Natural History and Antiquities" and has increased over time, with the acquisition of various collections, then merged in the collections of the "Lay Fraternity", with the significant contributions of the nineteenth century excavations. It's divided into 26 rooms, and has been recently renovated. The ground floor is topographically ordered, while in the first floor, the special sections (paleontology, prehistory, numismatics) and individual collections belonging to citizens of Arezzo (Bacci, Gamurrini, Funghini, Ceccatelli). Among the most significant findings of the Etruscan section, there are the precious jewels of the necropolis of Poggio del Sole, an imposing pediment polychrome decoration, made of plastic with a remarkable fight scenes, from St. James (480 BC), a series of interesting heads-portrait busts and votive by way of the Workers (II-I BC), as well as the remains of the magnificent sanctuary of Castelsecco (decorative plates, a stone altar and votive statues of children in diapers), a pebble in writing for divination and quinipodium, an exemplary coinage of considerable size of which are known only two specimens in the world. Of universal resonance are also the magnificent penthouse crater with Amazonomachy, masterpiece of pottery painter Euphronios (510-500), and the famous amphora from Casalta with the rape of Hippodamia, the school of the painter Meidias (420-410). The section includes Roman mosaics, bronzes, sculptures, inscriptions, funerary monuments, statues including that refined Empress Livia and that integrates a toga discovered in 1994 and tombs, for example those precious girl from "Puglia" and the other, Middle Ages, from "Pionta". Much space is devoted to the vessels from Arezzo, in the past also called "coral vases". The Museum has the largest collection in the world of this pottery produced in Arezzo between the middle of the first century BC and half of the AD, which made the city famous in antiquity. Also worth mentioning finally among the precious objects in the male portrait chrysography - gold on glass - (second half of the third century AD), which is one of the rarest and finest examples of this technique.