Chihuahua is best described as shaped as a large letter "L", with plains to the north and hills on both sides, as well as the south; it is crossed east-and-west by Teofilo Borunda Avenue, which follows the natural flow of the Chuviscar River. Borunda is crossed in the west by the Periferico de la Juventud, a major limited-access highway running north-and-south. The main entrance to the city from the north (from the direction of Ciudad Juárez) is Tecnológico Avenue, part of the Pan-American Highway.