Located in the province of Cáceres was declared a National Park with Law 1/2007 and becomes part of one of the 14 National Parks that Spain has.
Before reaching this status in 1979 was declared a Natural Park in 1988 Special Protection Area for Birds (SPA). In 2003 it was declared a Biosphere Reserve by UNESCO.
Its extension is 17,852 hectares, and the municipal terms that confer it are Casas de Miravete, Jaraicejo, Malpartida de Plasencia, Serradilla, Serrejón, Toril and Torrejón el Rubio.
The name Monfrague comes from the Roman: mons fragorum (fragoso mountain), this protected area extends to both sides of the Tagus river including the mouth and a valuable stretch of the river Tiétar, where we find the martin fisherman, myths, cormorants in addition to the otter.
The mountain ranges that delimit it are small and no more than 800 metres high and welcome the Mediterranean Forest in its pure state. Various ecosystems of high natural value alternate with the aforementioned Mediterranean forest, the rocky outcrop and the meadows.
The cork oaks, the scrub of rockroses, heathers and strawberry trees, the meadows of holm oaks and in the areas of rocky junipers, in those of rivera alisos, in the most thermal acebuche make Monfrague an exceptional natural reserve.
Currently Villarreal de San Carlos is the only population centre within the Park, its origin was as a resting place for the Cañada Real, then the current urban centre was created to accommodate the militia that Carlos III sent to protect the Puente del Cardenal. It is currently the administrative centre of the park with an information office, interpretation centre and exhibition, serving as a nerve centre for itineraries.