Sajama National Park — Bolivian AltiplanoCrossing.

A two-day ride from La Paz across the Bolivian altiplano to the country's highest peak — Nevado Sajama (6,542m), an extinct stratovolcano in Bolivia's oldest national park. The route crosses bone-dry altiplano at 4,000m, passes the Sistine Chapel of the Andes (a 17th-century church covered in Aymara murals), and descends into the queunua forest — the world's highest-altitude tree species — at the foot of Sajama itself.