Campo Soriano is a natural area between Terracina and Sonnino, now within the Monti Ausoni and Lago di Fondi Regional Natural Park. It was established as a natural monument in 1985, the first in Lazio, and according to the sources it is the only Italian natural monument recognised by the International Union for Conservation of Nature. It is a karst valley floor at about 360 metres, enclosed by Monte Romano, the highest at 864 metres, Monte Pannozzo, Monte Pecorone and Monte Cavallo Bianco, and the protected area covers 974 hectares.
What to see
The valley is a polje, a word of Slavic origin meaning flat field: a large basin about three kilometres long and between 200 and 300 metres wide, with a red, fertile floor and no surface streams, because the water seeps underground and feeds a vast network of caves and conduits. From the ground rise the hums, limestone monoliths shaped over millions of years by rain, frost and lichens.
The most famous is the Rava di San Domenico, about 18 metres high and known to all as the Cathedral, for shapes that recall a Gothic building. It marked the boundary between Terracina and Sonnino, with a cross carved into its sides; some bricks closing a niche suggest an old votive image, and the dedication to Saint Dominic of Sora is probably due to Benedictine monks from Fossanova and Terracina.
Visiting
Since 2002 a visitor centre with guest rooms has been running. The area is also an old end point of transhumance; trails and centre opening times should be checked with the park.
Our editors' tip
The natural monument was born of a fight: in 1978 a company from Cassino announced the opening of breccia quarries, and residents, environmentalists and politicians rose against it. The scars of the quarries can still be seen.
