An ancient harmony between agricultural activities and natural environment, revealing itself among the wide uplands characterized by the gentle hills where wetlands, woodlands, pastures and cultivated areas alternate. The uplands of Colfiorito and Plestini are made of seven karst hollows that in ancient times were lakes. The swamp of Colfiorito is currently the only upland area where the water remains all the year round and is subject to seasonal level variations. The other uplands are temporary flooded only after the rainfalls.
The swamp is a reference point for a large number of birds that build their nests among the groves of reeds, breed and feed on. For this reason, in 1995, the Umbria Region decided to protect it by establishing a regional park. It is part of the Ramsar Convention, that highlights the swamp's international significance as far as its natural features are concerned, and it has been recognized as a Special Protection Area (SPA) by the European Community thanks to its importance regarding the protection of the bird community living there.