The Diria National Park, until 2004 the Diria National Forest Wildlife Refuge, is a National Park of Costa Rica south of Santa Cruz in the Guanacaste Province, and forms part of the Tempisque Conservation Area. It protects both dry and at higher elevations humid tropical forest in the central highlands of the Nicoya Peninsula, including the watersheds of the Diria, Tigre, Verde and Enmedio rivers which have been created a terrain of deep valleys with steep slopes.
The park has a ranger station which is open daily from 8am to 4pm for visitors and tourists, and contains species such as deer, howler monkeys, anteaters and peccary, besides 134 known species of birds. There are also several rare tree species. It was originally designated as a protected zone in 1991 and then two years later it was became a National wildlife refuge.