The Tevere-Farfa Nature Reserve in Nazzano covers an area of over 700 acres comprehending the municipalities of Nazzano (Rome), Torrita Tiberina (Rome) and Montopoli in Sabina (Rieti). Its history is related to an artificial dam created between 1953 and 1955 by Enel (electricity company) and the morphology of the Tiber which in this section flows slowly forming large bends and meanders. The slow flow of the river and the junction to the Farfa stream have generated the Lake of Nazzano that over the years has housed many flora and fauna species that are typical of wetlands. The shore of the basin has been gradually edged by willows, poplars and alders creating a rare example of "riparian forest" in the Lazio region whilst the marsh canes and cattail have covered the river banks with debris that over time have gradually piled up beside the river banks or in the middle of the lake forming characteristic islets. Due to its strategic position for many bird migrations, Lake Nazzano is home to many bird species so much so that it was proclaimed “oasis of fauna protection” in 1968, in an agreement between Enel, the town of Nazzano and WWF Italy.

The extraordinary environmental asset of this area was then finally recognized in 1977 including the lake in the list of "wetlands of international interest" and the Nature Reserve recognition: the first protected area in the Lazio Region.