RN40 is the longest route in Argentina and one of the longest in the world alongside such routes as U.S. Route 66, Canada's Trans-Canada Highway, and Australia's Stuart Highway, more than long. At its traditional southern end near the city of Río Gallegos, it starts at sea level. It then crosses 20 national parks, 18 major rivers, and 27 passes in the Andes. Route 40's highest point is in Abra del Acay in Salta Province.