Parco regionale Diecimare, Regional nature reserve in Mercato San Severino, Italy.

The Parco regionale Diecimare covers 444 hectares of protected territory featuring Mediterranean scrubland, oak forests, and diverse geological formations across Monte Caruso and surrounding hills.

The protected area was established in 1980 and covers 444 hectares in the province of Salerno. In 1993 volunteers grouped under the WWF symbol founded the Diecimare park at Cava de' Tirreni. After the municipality did not renew the agreement, the WWF left the Cava de' Tirreni section in 2009 following a second fire at the visitor centre; since 2012 the association Terra Mia has helped revive it, while the Mercato San Severino section remains WWF-managed.

The park serves as a living laboratory for environmental education, hosting school groups and researchers while preserving traditional Mediterranean flora including holm oak, myrtle, and strawberry trees.

Visitors can reach the park by car via the Salerno-Naples highway, exiting at Cava de' Tirreni, or by public transport from local train stations with connecting bus services.

The park's visitor area at Mercato San Severino, still run by WWF Italia, holds a didactic farm and an equipped picnic area beside the trail network. The Cava de' Tirreni side passed to the Terra Mia association in 2012 after WWF left it in 2009, following a second fire at the visitor centre.