I recently returned from a month-long trip in Peru with friends Brett and Hongmai. We hiked the Inca trail, visited Machu Picchu, and camped in the Amazon rainforest.
One of the highlights of the trip for me was a week-long dirt bike motorcycle ride through Arequipa province. On the motorcycle trip, I visited the remote Cotahausi canyon, reportedly the deepest canyon in the world (more than twice as deep as the Grand Canyon!). Much of the motorcycle trip was at over 15,000 feet elevation, topping out at almost exactly 16,000 feet! The air was thin and cold, the sun harsh, and the scenery spectacular :-)
Brett has some great pictures online too.