The Janiculum also houses a Baroque fountain built by Pope Paul V in the late 17th century, the Fontana dell'Acqua Paola, and several foreign research institutions, including the American and Spanish Academies in Rome.
The Janiculum was a center for the cult of the god Janus: its position overlooking the city made it a good place for augurs to observe the auspices.
In Book VIII of the Aeneid by Virgil (Publius Vergilius Maro), King Evander shows Aeneas (the Trojan hero of this epic poem) the ruins of Saturnia and Janiculum on the Capitoline Hill near the Arcadian city of Pallanteum (the future site of Rome) (see line 54, Bk.
As revealed by excavations in the 1990s under the present American Academy in Rome,[3] they sat astride the aqueduct Aqua Traiana and were in brick-faced concrete with a cocciopesto floor.
It appeared that the northern mill race had 3 or 4 millwheels of 2.30 m diameter and width about 1.65 m to provide a sufficiently large working area, but only 2.6 m between their axle centres, which must have reduced efficiency due to turbulence between them.
This site was chosen for its proximity to the Villa Doria Pamphili, where Garibaldi mounted a military defense of the short-lived Roman Republic in late April 1849.
A 2011 guide published by the local Associazione Amilcare Cipriani group, after an extensive restoration of these monuments, lists a total of 84 busts on the hill.