Those brave and skilled enough to attempt these climbs should consider themselves amongst the greatest athletes in the world.
La Dura Dura - Oliana, Spain
This Spanish route was taken on by the world's top two sports climbers, Adam Ondra and Chris Sharma. La Dura Dura is famous for its sheer vertical cliff face with an especially sparse distribution of features. The crux, or toughest part of the climb, involves a high heel, side pull, and tiny crimp that would seem like a bare stretch of rock to the naked eye. The next move requires the climber to miss out a clip, meaning that a fall results in a terrifying 'whipper,' or stomach-jerking fall.
Vasil Vasil - Sloup, Czech Republic
At a jaw-dropping 9b+, this route is a force to be reckoned with. Half a year after Dura Dura, Czech climbing superstar Adam Ondra stood face to face with a new rocky opponent. This was a grimy climb that Ondra described as "Short, painful, and in dirty place." In his interview with Planet Mountain magazine, Ondra said: "Well, if you look at it there's nothing impressive about it really. But for me it had something special. The crux looked horrible, impossible actually. It fascinated me. And so I simply couldn't leave it unclimbed!"
Cerro Torre - Argentine Patagonia
Cerro Terre is a mountain with a spectacular view of the snow-covered Southern Patagonian Ice Field. Since the area is full of good routes, nobody had even considered the southeast ridge, home to the infamous Compressor Route, as a potential free climb. Until David Lama, an Austrian sport climbing champion stepped up to the plate. He took on the volcanic finger that looms over the Torre glacier floor. On the unnerving crux pitch almost a mile above the glacier, Lama took repeated falls of up to 35 feet.
Wolverine - Helmcken Falls, British Columbia
This climb differs from the others on this list in that the temperature here is around 20 degrees colder. The famous waterfall sprays foam across the cave, which then freezes, leaving thousands of otherworldly ice stalactites hanging precariously from the cave roof. Ice climbing involves throwing ice aces and crampons into the route, praying that the ice will hold. As it's structured around the roof, the route begins vertical, before morphing into a horizontal plane that saps the strength. When Will Gadd stumbled across the site, he announced that it was the coolest that he'd ever seen in the world, and told himself that he would be back. Sure enough, Gadd returned with climbing partner Tim Emmett, completing the route, and rating it WI10, a whole two grades higher than anything ever climbed before.
Eternal Flame - Trango Tower, Pakistan
To say that this route, nestled in the Pakistani Korakoram Mountains, is demanding wouldn't be doing it justice. The route features all the best aspects of Alpine climbing, such as hand jamming, ?lay-offs? and a 3,000 foot route that tops out into a 20,508 foot summit, offering magnificent views of the surrounding mountain range. This climb was only completed in 2009, when Bavarian brothers Alexander and Thomas Huber freed it in four days.