The territory of Nera River Park has a mainly
longitudinal course: it is crossed by the middle - lower course of the
river Nera for about 20 kilometers and is characterized by a narrow
valley bottom dominated by high mountains covered with woods.
Its flora is diversified: olive groves along the whole piedmont strip and part of the mountain area; broadleaf trees on the steep mountain slopes; herbaceous species, above all Graminaceae suitable for the spring pasture of cattle and sheep, on the highest mountains; arboreal and shrubby species of the Mediterranean maquis - ilex trees (Quercus ilex), Aleppo pines (Pinus halepensis), and Strawberry trees (Arbutus unedo) - in the woods. A very rare and endemic species is Ephedra major or Ephedra nebrodensis, an example of surviving flora of the Tertiary Age, with only a few stations in Italy, among which the most recess rocky areas of the Park.
The fauna can be divided in two categories: the fauna of the watercourses, among which the brown trout (Salmo trutta fario), and the mountain fauna including several birds of prey, like the Short-toed Eagle (Circaetus gallicus) and the Kestrel (Falco tinnunculus) and, in the most inaccessible and lonely areas, the wild cat (Felis silvestris) and the pine marten (Martes martes).
There are thousands of bats (Rhinolophus ferrumequinum) which, during the winter, find shelter in the caves of Marmore Waterfall.
Marmore Waterfall is an artificial waterfall formed by the river Velino
which, after a route of about 90 kilometers and after crossing, along
its final stretch, Rieti plain and a travertine balcony, plunges down
into the river Nera, running set in the underlying valley.
Its history begins in 271 BC, with the first reclamation measure in Valle del Velino by the Roman consul Curio Dentato and continues with the subsequent measures carried out by the Commune of Rieti in 1422, and by the Popes Paul III Farnese and Clement VIII, in 1547 and 1601 respectively.
Celebrated in the verses by Virgil and Dante and immortalized by the 17th century landscape painters, Marmore Waterfall became in the 18th and 19th century a privileged destination for the Grand Tour travellers who completed in Italy their art education training, and was definitively consecrated by Lord Byron in the 4th canto of "Childe Harold's Pilgrimage".
Chosen as symbol of strength and energy, in 1945 its image became the logo of "Società Terni", the biggest industry of the town and one of the largest firms in Italy.
Galleto Hydroelectric Power Station was built by "Società Terni per
l'Industria e l'Elettricità", according to a project by the Architect
Cesare Bazzani, to meet the growing need of electric energy by the
industry of Terni, in particular by the arms industry, and was
inaugurated in 1929.
During World War II, the Allied Forces tried more than once to destroy it and, in June 1944, the retreating Germans blew it up.
At the end of 1945, the 4 production units had been restored.
After 1962, the power station was nationalized and became part of Enel, which in 1973 doubled them with Monte Sant'Angelo power station.
In 2001, "Società Endesa Italia" of ENDESA Group purchased from Enel all the hydroelectric power stations of the Nucelus of Terni, for which today Galleto power station together with the annexed Monte Sant'Angelo power station, produces about the 50% of the total energy.
Galleto power station is supplied by the waters of Nera-Velino system, flowing from Piediluco basin through the so-called "Drizzagno" channel.