4 once-in-a-lifetime treks for serious adventurers - SilverKris

"A uniquely demanding crossing that sends you downhill first before forcing a major climb back out, the route from the North Rim involves an almost 2,000 m descent over roughly 23 km followed the next day by about a 1,400 m ascent over 15 km. Scenery shifts dramatically from pine forests and snow at rim level to hot desert on the canyon floor. Hikers can ease the knee-jarring sections by riding a mule and breaking the journey with an overnight stay at an exclusive canyon-floor lodge; fewer than 1% of visitors attempt the crossing on foot." - SilverKris