Tivoli, Latin Tibur, town and episcopal see, Lazio (Latium) regione, central Italy. It is picturesquely situated on the western slopes of the Sabine Hills.
It is an important landmark in the history of architecture, and its monuments are among the most impressive to survive from antiquity.. Among the remains of wealthy Roman residences in the immediate neighborhood, the most important are those of the one that was subsequently acquired by the emperor Hadrian in the 1st century to become the nucleus of his famous villa. Hadrian’s Villa was the largest and most sumptuous imperial villa in the Roman Empire. It begun about 118 CE and took about 10 years to build. It lies in a plain below the hill town of Tivoli. The villa contained palaces, libraries, guest quarters, public baths, and two theaters. The remnants of many great brick and concrete structures remain.