Piedra Monastery is located in one of the most barren areas of Aragon. Its origins go back to the year 1194, when Alonso II, "the Chaste", and his wife Doña Sancha donated an old Moorish castle to the Poblet monks to build a monastery and establish the Christian faith in the region. In 1840, Pablo Muntadas Campeny bought the monastery and carried on with its farming and livestock raising activities. His son, Juan Federico Muntadas, would give shape to the park by making changes, building paths and walkways and planting. In 1860, after the Iris cavern was discovered, it was opened to the public. The first fish farm in Spain was created in 1867 by naturalising the common trout and white-clawed crayfish in the waters of the Piedra River. This farm continues to supply Aragonese rivers with species for restocking. The result of these activities is the garden as we know it today, which was designated a National Scenic Site in 1940.