Castel Sant'Angelo (Sant'Angelo), a powerful block of which still dominates the panorama of Rome, originally served as the burial place of the emperors, and was only turned into a fortress in the Middle Ages. The castle is also known as the Mausoleum of Hadrian. To join this magnificent monument to the Field of Mars, it was constructed bridge Sant'Angelo. It consists of three huge central arches and two inclined platforms supported by three arches on the right bank and two - on the left.

The scheme of construction of the mausoleum, the building included in the Castel Sant'Angelo, in the Middle Ages, mostly remained unchanged. The building stands on a huge quadrangular base, the length of each side - 89 meters, height - 15 meters. On this basis, a cylindrical drum is 21 meters high, surrounded by radial walls. Top of this drum poured a huge mound of earth planted with trees, and on its edges fitted marble statues. The exterior is faced with moonstone (type of marble) with signs, incorporated the entire circumference of the wall on which the names and titles of those who were buried inside the mausoleum. Burial chamber, located in the heart of a massive drum - square in shape with three rectangular niches. In this room, we placed an urn with the ashes of the emperors.

Perhaps as early as 403, Emperor Honorius incorporated it into a bastion of building defensive walls of Aurelian. By becoming a fortress, it was subjected to the 537 year siege by the Goths led Vitiga. Its transformation into a castle there in the tenth century. Today the castle is a powerful fortress on a square base with four round towers at the corners, bearing the names of the Apostles: Sv.Matfeya, St. John, St. Mark and St. Luke. During the pontificate of Pope Benedict IX was established on the basis of a cylindrical body, repeating the scheme of construction of the mausoleum of Hadrian. Further changes have been introduced to the castle during the reign of the popes Alexander VI and Julius II. At last at the top of the castle, as a frame of the apartment pope, was built loggia.

Upstairs there is an observation terrace, above which hovers Angel, gave its name to the castle, which is on its wings, according to legend, brought deliverance saving Rome from a terrible plague raged during the pontificate of Gregory the Great. Inside the castle are now in the National War Museum and the Museum of Art.