National Geographic named Boulder the Happiest City in the United States a few years ago, and it was the first of many occasions that Boulder has been named the happiest of one of the happiest places.

So what makes Boulder so great? Locals will point to the eclectic mix of friendly people, the amazing outdoor activities, and an emphasis on local art, and they wouldn’t be far off. National Geographic made their ranking based on many factors, including Boulder‘s healthy eating, civic engagement, financial security and vacation time, how easy it is to get around on foot or by bike, and even how frequently they visit the dentist.

“Bolstered by a sense of community, access to nature, sustainable urban development and preservation policies, and perhaps even that clean mountain air, Boulderites overwhelmingly feel ‘active and productive every day,’” according to National Geographic. “Life is not always rosy in the Rockies-stress is on the rise; on average, 49 percent of locals surveyed reported feeling stress-but the qualities that keep Boulder on top make this city America’s happiest.”

Access to nature and all of its benefits was one of the top reasons given for Boulder‘s happiness. There are over 300 miles of bike trails in Boulder that make residents happy.