When you walk down a hill, you have to work hard to keep from sliding straight down. If it's really steep, you might have to zigzag back and forth sideways, so you go down the hill just a little bit at a time. That's what we see in this photo of the "switchbacks" on the side of Beacon Rock in Washington state. The 848-foot-tall, blob-shaped rock might be the second biggest rock in the world, after the Rock of Gibraltar. In 1915 a guy named Henry Biddle bought the whole rock for just $1, and built trails so people could climb the rock and look out at the beautiful river next to it. These switchbacks let people walk from 248 feet above the river all the way to the top, and back down again. There are about 50 of these switchback pieces, so if you're going to start the walk, make sure you'll have enough energy to come back down when you're done!