From Etruscan times Tibur, a Sabine city, was the seat of the Tiburtine Sibyl. There are two small temples above the falls, the rotunda traditionally associated with Vesta and the rectangular one with the Sibyl of Tibur, whom Varro calls Albunea, the water nymph who was worshipped on the banks of the Anio as a tenth Sibyl added to the nine mentioned by the Greek writers. In the nearby woods, Faunus had a sacred grove. During the Roman age Tibur maintained a certain importance, being on the way (the Via Tiburtina, extended as the Via Valeria) that Romans had to follow to cross the mountain regions of the Apennines towards the Abruzzo, the region where lived some of its fiercest enemies such as Volsci, Sabini and Samnites.