Parco Fluviale del Tevere

A stretch of the Tiber watercourse between the area in the south-east of Todi and Corbara Lake runs between high and indented banks. The gorges are set between the ridges of Peglia and Croce di Serra mountains. The calcareous nature of the mountains leads to the formation of deep circular abysses looking like swallow holes. These mountains, during the Tertiary and Quaternary periods, delimited the big Tiberino Lake.