Riserva naturale Duna Feniglia, State nature reserve between Orbetello Lagoon and Tyrrhenian Sea, Italy.

The Duna Feniglia is a state nature reserve on a 6 km sand tombolo linking the hill of Ansedonia to Monte Argentario, in the municipality of Orbetello. The strip, 474 hectares in all, is covered by a stone pine forest planted after 1910, with a sandy seaward edge and salt-marsh vegetation facing the Orbetello Lagoon. A dirt road built between 1928 and 1940 crosses it, closed to motor vehicles.

Orbetello sold the Feniglia to private owners in 1804, who used it for grazing and timber; the forest law of 1877 removed protection and the dune eroded. In 1910 the area became state forest and was reforested with maritime and stone pines, creating about 460 hectares of woodland. It was declared a protection forest reserve in 1971.

The name Feniglia comes from the tombolo that links Ansedonia to Monte Argentario. Since 1910 the pinewood has been managed for resin tapping and for collecting stone-pine seeds used in food production. The deer introduced in the 1950s from Castel Porziano keep invasive broadleaf growth in check.

The reserve is accessible through two entrances, one from the Aurelia road and another from Argentario, with free access year-round. The terrain is mostly flat, making walking straightforward, and marked paths show the way through the forest and down to the beaches.

The forest is home to a freely roaming deer population that grazes among the stone pines. Every kilometer or so, paths lead down to hidden beaches where you can leave the forest behind and settle onto the sand.