The Marsiliana Nature Park is located in Massa Marittima and covers a surface area of approximately 450 hectares, almost entirely in the Montioni Interprovincial Park.
Owned by the state, the park is managed by the forestry corps staff through the former state-owned forests agency. It aims to preserve and promote plant associations and natural habitats, maintain biodiversity and safeguard wild fauna.
The park is situated in a hilly area with an average altitude of 120-180 metres above sea level, dotted with agricultural areas alternating with natural vegetation consisting of evergreen sclerophyll copses.