From NR Cerro Castillo five times crosses the river in a wooded ravine and arrive at a glacial valley with large masses of rock, among which highlights the Piedra del Conde (km. 76). At km 83 you will cross the Portezuelo Ibañez (1,120 mt.). At Km 85 begins the Cuesta del Diablo zigzag overlooking the river valley Ibanez, who comes from an ice road to the west and is born of the Hudson volcano (hence the color of ashes). To the right closes the valley Castillo Hill (2,675 m).