The Sibillini National Park is a protected area of the Sibillini Mountain and extends between the regions of Marche and Umbria. The Park, established in 1993, is part of the main axis of the Apennines sloping down to east and west, characterized by a wide variety of landscapes and natural environments: the valley bottoms of the rivers are divided into narrow gorges and impressive, as the striking Gole dell'Infernaccio; higher, many forests (mainly beech) surround crown valleys. The western side slopes gently toward the Umbria with its famous Castelluccio Plains. Situated between the steep walls, below the summit of Vettore Mount, there is the Lake of Pilate, one of the few glacial lakes present in the Apennines and the only natural source of Marche. In popular tradition, it takes its name from the legend according to which, in its waters, it would end the body of Pontius Pilate sentenced to death by Tiberius. The "Big Ring of Sibillini" is a hiking trail of about 120 km, which is spread across the length of the park, walking or mountain biking. The Park is home to several tourist information centers, with functions of documentation and thematic analysis.