Earth Day: Where are the most popular U.S. National Parks on Facebook?

In light of Earth Day, Facebook recently put out a list of the most checked-in U.S. National Parks, with Arizona’s Grand Canyon leading the list.

Of all the people who checked into a U.S. National Park on Facebook in 2013, 9 percent visited more than one National Park in that year. Interestingly, 12 percent of those who checked into a National Park on Facebook last year weren’t from the U.S. The top countries of international visitors to U.S. National Parks (according to Facebook check-in data): the U.K.,