The Patagonia Marathon, Chile
Credit: Getty Images

Who: 1,000 runners

When: September 27, 2014

Why it's unique: A tree is planted for each runner in the marathon (and 39-mile ultra marathon) who winds his or her way along the tierra of Torres Del Paine National Park, land that has been ravaged by fires in recent years. Runners have to contend with wind, elevation, and the overall beauty in this southerly stretch of Patagonian wilderness. In September 2014, they introduced a 40-mile ultra marathon version. [patagonianinternationalmarathon.com]