A Timed Lava Course made out of Pistons and Redstone Repeaters. It's tougher than it looks! Took me about 4 hours from start to finish. The sand falls back under the lava after a set amount of time, so if you stay in one place for too long, you'll die.

Music is my own remix of Bowser in the Sky World from Super Mario 64 - you can find it here: http://www.youtube.com/user/MusicalWolfe?feature=mhum#p/u/48/VpvrAQ6W57A

Pistons by Hippoplatimus: http://www.minecraftforum.net/viewtopic.php?f=1032&t=247686