Arizona's northeastern corner joins three other states—the only place in the U.S. where four states share a common point. A monument run by the Navajo tribe (whose reservation encompasses this corner of the state) allows visitors to stand in Utah, Colorado, New Mexico and Arizona simultaneously. If you're driving past the spot (on Highway 160) and have an extra 10 minutes (and a couple of dollars), it's worth a stop. If not, don't go out of your way to see it. 275 mi/440 km northeast of Phoenix.