As recently as April 2014, the Gallup-Healthways Well-Being Index indicated Boulder, Colorado as the skinniest city in the United States. Since the pedestrian-friendly city rests in the cradle of the Rocky Mountain foothills, with plenty of nearby opportunities to hike, the ranking is perhaps no surprise to Boulder's 100,000 residents. It certainly comes as no surprise to guides at Boulder Walking Tours, who make their living showing off the city's footpaths through its downtown historic districts.

On one of their signature tours, guides take up to eight guests to explore Boulder's still-operational Chautauqua campus, where an adult-educational movement has thrived since the late 19th century. The morning-long tour benefits from stunning views of the Flatirons, deftly told anecdotes of local Chautauquans, and historical photographs that show off how far picture-taking technology has come.