TIVOLI (tiv'o-le), (anc. Tibur, q.v.), a town and episcopal see, province of Rome, 18 m. E.N.E. of Rome by road and tram way, 244 m. by rail, 76o ft. above sea-level. Pop. (1931), 15,312 (town), 19,223 (commune). Tivoli lies on the west of the Sabine mts., where the river Anio issues from them, upon a limestone rock above the river. The town on one side overlooks the Cam pagna di Roma and Rome itself, on the other the deep gorge of the Anio, with its lofty falls, and the environs are very beautiful. The Villa d'Este, begun in 1549 by Pirro Ligorio for Cardinal Ippolito d'Este the younger, has the finest example of a Renais sance garden in Italy ; it was erected on a steep slope, with many terraces, and embellished with numerous fountains. The castle was built (146o) by Pius II. on the site of the amphitheatre; it is now a prison. The town contains numerous old churches and houses : the cathedral has a fine 12th century campanile, and con tains an old copy of the painting of Christ in the Sancta Sanctorum in Rome; S. Silvestro, iith century paintings; S. Giovanni Evan
gelista, paintings by an unknown follower of Melozzo da Forli, etc. In November 1826 a flood of the Anio led to a change in its course, and threatened to carry away the town. A new channel, consisting of two parallel tunnels 290 and 33o yd. long, was therefore made to the north-east in 1826-35, and on emerging from these the river has a fall of 354 ft. Farther north-west are smaller falls (the cascatelle) of that portion of the river which is carried through the town and serves for industrial purposes. Five miles W. are the sulphur baths of Acque Albule, which were known to the ancients, and are still frequented. The temperature of the water is 75.2° F. The falls in the river afford electric power for lighting Rome and driving its trams, as well as for driving several factories, etc., in Tivoli itself.