Whether wearing a cape jumping off the roof to test your flight abilities when you’re six, or dancing on a wire dozens of stories off the ground when you’re thirty, people manage to put themselves in danger for the sake of fame, fortune, self-discovery, or exploration.

Here are some of the most extreme examples of people pushing the envelope.

The Skydive from Hell (or The Heavens)

Joseph Kittinger is most notably remembered for his incredible series of high altitude balloon jumps, the last of which still holds the world record today for highest balloon ascent, highest parachute jump, and fastest speed by a human being through the atmosphere (614 mph). He is the only human to have ever broken the sound barrier without use of any mechanical equipment. Later attempts to break his record for highest ascent in a balloon led to the death of the occupants.

The World Trade Center Tightrope Dance

Philipe Petit strung a 140 foot steel cable between the “Twin Towers” (1,368 feet off the ground) and stepped off the ledge. He spent 45 minutes on the wire, crossing between the towers 8 times. The police were dispatched to arrest him as soon as they realized what was going on, but Petit continued to enjoy himself on his wire until the threat of a helicopter plucking him off the wire (and rain) helped him end his tightrope dance.

The Land Speed Record

Andy Green currently holds the land speed record at 766 mph. These trials are typically held at salt flats because of their smooth surface, but even one pebble out of place could easily turn a vehicle into a speeding ball of flame.

The Air Speed Record

4,534 mph, set by Pete Knight. At that rate, you could fly from the earth to the moon in 52 hours.

Motorcycle Jump

Robbie Maddison recently set a new record for longest motorcycle jump with 346 feet. Evil Knievel’s longest jump was 151 feet.

The “Human Jet”

Yves Rossy decided one day to cross the English Channel -- using a jetpack. He made the crossing in under 10 minutes, reaching a speed of 125 mph.

The Constant Swimmer

Martin Strel swims swam for 84 hours and 10 minutes straight up the Danube river without a break. Just to secure his place in the swimming hall of fame, he also swam the Mississippi River (although not constantly), covering the 2,360 miles in 68 days.

The Everest Summit (Sans Oxygen)

Reinhold Messner went up Everest -- solo for the last 3 days -- without any supplemental oxygen. With air one third the density as at sea level, breathing is near impossible at 29,000 feet.

The Largest/Longest/Craziest BASE jump

At a height of 21,666 feet, Glenn Singleman and Heather Swan took a leap off of Meru Peak and into the record books. They free fell for over two minutes and landed on a glacier, breaking all previous held records for base jumping height and distance. They had to mountaineer their way up the almost 22,000 foot mountain before jumping.

Bungee Jumping

The most dangerous and largest recorded bungee jump currently belongs to David Barlia, who bungeed out of a helicopter and fell for almost 6,000 feet.

Free Diving

With only one breath of air, Patrick Musimu dove to a depth of 687 feet. That’s 298 pounds per square inch of pressure on his body, and about 20 atmosphere’s worth of pressure compressing his lungs and body. He currently holds the free diving record by over 120 feet.

The Ice Man

Wim Hof sat in a tub of ice, up to his neck, for 1 hour and 31 minutes. He holds nine ice related world records, and claims he can control his body temperature using the Tantric practice of Tummo.

Niagara Falls by Barrel

In 1901 Annie Tayler was the first person to go over Niagara Falls in a barrel and survive.