The most important contributors to a roller coaster's ability to instill fear in its patrons are its speed and height. The minds behind the Kingda Ka at Six Flags Great Adventure in Jackson, New Jersey clearly understood this, as they combined speed and height to create the scariest roller coaster in the world.

Kamikaze. On the other hand, the Kamikaze (also known as the Hammer) is one of the scariest carnival rides. With a hammer-like look, the Kamikaze is a pendulum that swings back and forth in a massive sweeping motion. Passenger cars are located on the end, where the g-forces are highest.

The Steel Dragon 2000 is the longest roller coaster in the world, measuring a whopping 8,133 feet in length.

However, I deal with a lot more post-coaster nausea now than I ever did as a kid, and can't tear through ride after ride as fast as I used to. Now I know why! Your vestibular system loses efficiency as you age, making it harder for your inner ear to reorient your balance after being whipped around on a thrill ride.