Vulture's Knob is not for the brittle-boned. But it has some of the most dynamic and extreme terrain around -- which you'll realize when you unexpectedly find yourself riding down the roof of a wooden shack. Other obstacles dare you to cross them -- like the "Rainbow Bridge," which takes your wheels in an arc about 10 feet off the ground, and a high-slung suspension bridge that shakes and creaks as you pedal furiously to the other side. Luckily, many of the stunts give you the option of going around them. Others, however, like a super-skinny bridge over a swamp, are the only way to keep going. Might want to bring your bathing suit for that one.