From the World Heritage inscription:
Villa Adriana is a masterpiece that uniquely brings together the highest expressions of the material cultures of the ancient Mediterranean world. Study its monuments played a crucial role in the rediscovery of the elements of classical architecture by the architects of the Renaissance and the Baroque period. It also profoundly influenced many 19th- and 20th-century architects and designers.
The villa covers more than 120 ha on the slopes of the Tiburtine Hills. It was originally occupied by a late Republican villa, the property of Hadrian’s wife, Vibia Sabina. The imperial residence was built over it in AD 118-38. It was a symbol of a power that was gradually becoming absolute and which distanced itself from the capital. After Hadrian’s death in 138, his successors preferred Rome as their permanent residence, but the villa continued to be enlarged and further embellished. Constantine the Great is alleged to have removed some of its finer pieces to his new capital, Byzantium. The villa was sacked and plundered by successive barbarian invaders and fell into neglect, being used as a quarry by builders and lime-burners. Interest in the ruins was rekindled in the 15th century by Pope Pius II (Aeneas Silvius). Excavations to recover its glories were ordered by Alexander VI at the beginning of the 16th century. When Cardinal Ippolito II d’Este began to construct his nearby Villa d’Este he continued the excavations, supervised by his architect Pirro Ligorio, to obtain works of art to adorn it.
The many structures are arranged without any overall plan within this area. They fall into four specific groups. The first group includes the Greek Theatre and the Temple of Aphrodite Cnidi. The theatre, which is in a good state of conservation, although only fragmentary, is of conventional design. Its cavea is cut into the hillside and is some 36 m in diameter. The small circular temple is situated in a large semi-circular exedra.
The second group, including the Maritime Theatre, Court of the Libraries, Latin and Greek Libraries, Imperial Palace and Golden Square, is the core of the complex, aligned with the Vale of Tempe. The various elements are grouped round four peristyles. The Maritime (or Naval) Theatre is a circular structure 43 m in diameter; the Ionic marble peristyle encloses a circular moat surrounding a central island with a miniature villa. The Court of the Libraries, the oldest part of the ensemble, is a colonnaded portico with a nymphaeum on its northern side. The two ‘libraries’ are reached by passages on either side of the nymphaeum. The palace consists of a complex of rooms around a courtyard. The Golden Square is one of the most impressive buildings in the complex: the vast peristyle is surrounded by a two-aisled portico with alternate columns in cipollino marble and Egyptian granite
The third group comprises the Pecile, Stadium and its associated buildings, Small and Large Thermae, Canopus, Serapeum and Cento Camerelle. The Pecile (or Poikile) is a reproduction of an imposing structure in Athens famous for its paintings and its associations with the Stoic philosophers which consists of a large rectangular enclosure. Part of its massive walls survives; they had colonnades on either side. In the centre was a rectangular pool enclosed by a free space, perhaps used as a racetrack. The two sets of baths are conventional in form. The smaller is considered to have been used exclusively by women. The Canopus is an elongated canal imitating the famous sanctuary of Serapis near Alexandria. The semi-circular exedra of the Serapeum is located at its southern end.
The fourth group includes the Lily Pond, Roccabruna Tower and Academy. The tower is a complex of buildings, the purpose of which is not clearly established. In addition to these structures, there is a complex of underground elements, including cryptoportici and underground galleries, used for internal communications and storage. A number of the ancient structures are overlaid by a series of farmhouses and other buildings, mostly from the 18th century. They were built directly on the earlier foundations and it is difficult to dissociate them from the ancient structures.
The second of the two villa world heritage sites in Tivoli is Hadrian’s Villa.
Of the two villas, Hadrian’s gets only a small fraction of the number of visitors that the Villa d’Este gets. It is a much larger site which requires more walking and most of the site are ruins. That being said, they might be better ruins than the Roman Forum itself and it is one of the few places near Rome where you can view ruins without large crowds.
You can still see the rooms, pools and baths of the palace even though much of the facing marble has been removed. You can also still see bits of original fresco near the ceiling of the baths as well as original marble work in some places.
If you visit the villa, you should also visit the Villa d’Este and the Vatican Museum in conjunction. Both sites have material and art objects taken from Hadrian’s Villa. Many of the statues dedicated to Hadrian’s young male lover Antinous in the Vatican Museum and much of the marble is now in the Villa d’Este.
The villa is only 10 minutes by car from the Villa d’Este and and 30-60 minutes from the center of Rome depending on traffic. The villa is not near the center of town, so if you take a bus or train, you will need to take a local bus or taxi to get to the site.
The villa is an exceptional site and given its proximity to Rome should be considered a must see for anyone interested in Roman history.
My day trip to Tivoli tour of the villas was arranged and provided by Walks of Italy.