This reserve stretches over 400 hectares along the coast and preserves one of the last remaining parts of an ancient forest, known as the Selva di Nettuno, which covered a large part of the Tyrrhenian coastal plains until the 18th century.
The area is of particular interest because of its macchia mediterranea scrub vegetation and the presence of a number of sulphurous springs.
Visitors are usually immediately struck by the yellow colour of the earth, revealing the presence of underground sulphur deposits, along with small white and yellow tufo reefs jutting out into the sea where bee-eaters build their nests.
There are forests of ilex and cork trees, with undergrowth of arbutus berries, hawthorns and heather, along with wetlands made up of oak groves.
Swampy areas are filled with reeds and marsh canes and closer to the coast there are clumps of broom, myrtle, lentisk and wind resistant blackberry bushes.
The dunes are covered with typical flora such as seaside camomile, sea medick and the rare many-spiked flatsedge.
Compared with the last century there is now a considerably reduced variety of fauna, but this area is known for wild rabbits, dormice, foxes and weasels along with a few species of reptiles.
There is also the recently reintroduced Hermann tortoise and the swamp turtle. This area also has an interesting range of bird life, especially since it is one of the stopping off places on the migration routes.
The Visitors’ Centre offers information, runs an environmental workshop and has a specialised media library and archive. You can also see a botanic vegetable garden, areas with tortoises, turtles and Maremma wild boar, a small farm zoo with various kinds of mules and donkeys and finally an aviary and a pool used to treat wounded animals.
On request you can also visit Caldane Tower (Torre delle Caldane), after which the reserve is named, which has a museum inside that recreates the history of the reserve and the remains of the one of the many coastal villas that the Romans built during the Imperial Age.
The villa was discovered in 1999 and dates back to between the 2nd and 3rd centuries AD. Today you can see rooms decorated with mosaics and marbles, including parts of a thermal bath. There are also more recent “remains” in the form of the sentry points dug by the British after the landings at Anzio in 1944.