• Lazio

• Regional Nature Reserves

A gentle series of hills between the Tiber Valley and Cornicolani Mountains, covered by olive groves, woods, and fodder fields. A calcareous territory where the karstic phenomena have given origin to caves, dolines, and swallow holes. The most spectacular one, "Pozzo del Merro", is an abyss opening in the soil, whose walls are completely covered by vegetation and whose bottom is occupied by a very deep lake.