What's a theme park without a roller coaster? Coasters got their start in the coal mines of Pennsylvania. Small cars running on tracks were built to haul coal down the mountain. On the weekend people could pay money to take a thrill-ride in the car. Today's roller coasters are very popular steel beasts. Cars on some coasters go over 100 miles per hour. Some coasters that are over 400 feet tall. As scary as they are, many people love roller coasters.