10 Steamy Facts About Old Faithful

(via Mental Floss) Yellowstone National Park attracts more than 4 million visitors per year as the fifth-most visited national park in the U.S. People come to this 3472-square-mile tract of Western wilderness for its towering mountains, charismatic megafauna, and, of course, its spectacular geysers. While there are loads of hydrothermal features to see, the most iconic geyser by far is Old Faithful, named by explorers in 1870. Here are a few facts about this Wyoming wonder.