One of Mexico's most spectacular natural attractions is where the Sierra Madre mountain range forms one of the longest and deepest canyon systems in the world, covering over 40000 square kilometres of rugged land. Three of the canyons – Urique (1890m), Sinforosa (1840m) and Batopilas (1810m) - are not only deeper than Arizona's famous Grand Canyon (1433m), they are considered to be the world's eighth, ninth and tenth deepest, respectively. Known in Spanish as Las Barrancas del Cobre, or Copper Canyon, this natural marvel boasts beautiful scenery and an unforgettable train ride, and is home to Mexico's Tarahumara Indians.

The Tarahumara - who call themselves Raramuri, or the "light footed ones" in reference to their running skills - are often described as reclusive, but weren't always that way. When the Spanish arrived, the Tarahumara inhabited Chihuahua's central plains. In trying to escape forced labor in Spanish-owned mines or haciendas, they slowly retreated into the canyons. Now they exclusively inhabit the Sierra Tarahumara, though the women, colourfully dressed in multilayered skirts and frilly tops, are often seen on the streets of Chihuahua selling their wares.

Today, the Copper Canyon Express railroad stretches for 480 kilometres across the mountains, taking passengers over 35 bridges and through 86 tunnels.