Roller coasters and other such thrill rides are fun, but imagine reaching speed of up to 100 miles per hour on a metal cable, with nothing more then a harness, a helmet... and the air below you.

Around the world, zip lines have become an adrenaline seeker's favorite, literally allowing you to hurtle through awe-inspiring landscapes at jaw-dropping speeds. In some cases, the mere presence of a zip line can be a decision-maker between two competing travel destinations. Not sure about all this? Strap in and enjoy the ride on these videos, which feature some of best zip lines in the world.

At a height of 918 feet, speeds of up to 100 mph, and spanning just over a mile, Sun City, South Africa boasts the steepest, fastest, tallest zip line on the globe. On this particular line, the rider zips down the cable while flat, rocket-like. This particular zip line gives the rider the experience of being able to fly like a bird... well, like a very, very, very fast bird.

From sandy beaches to indoor water parks, surfing is a popular sport worldwide. Needless to say, funny surf wipeouts are just as popular... and oftentimes far more amusing!

See below for some of the best surfing wipeouts anywhere. And remember: if you're visiting the beach this summer, maybe you should take some surfing lessons before you wax your board. Just saying.

This poor guy is cut down hard and fast by a small but painful wave.