Fort Collins.

Fort Collins started as an Army fort in 1864 and grew into a university town of about 175,000 at the base of the Rocky Mountain foothills, an hour north of Denver and forty-five minutes short of the Wyoming line. Colorado State University and its roughly 34,000 students give the place a steady intellectual pulse; Old Town gives it a heart. The historic brick core, all Victorian storefronts and tree-lined avenues, is said to have inspired Disneyland's Main Street USA, and locals guard the resemblance. Sitting near 5,000 feet, the city gets more than 300 days of sun a year and four dry, legible seasons.

The supporting cast is what makes it work for retirees. This is one of the safer cities its size in Colorado, with a nationally recognized, award-winning Senior Center running deep fitness, arts, and social programming. UCHealth Poudre Valley Hospital sits in town, ranked No. 5 in the state, and Medical Center of the Rockies, a Level I trauma center, is twenty minutes south in Loveland. CSU is the quiet engine underneath all of it: public lectures, concerts at the University Center for the Arts, the Gardens on Spring Creek, a calendar of festivals, farmers markets, and the densest craft-brewery scene in Colorado, all open to the town.

But the organizing fact of Fort Collins is the terrain at its back. Rocky Mountain National Park is 45 minutes up the Cache la Poudre canyon. Horsetooth Reservoir, a six-mile foothills lake, sits at the western edge of town, with Lory State Park and Roosevelt National Forest just past it. The Poudre itself, Colorado's only federally designated Wild and Scenic river, runs out of the high country through the north of the city, and more than 280 miles of trails and bike lanes thread the whole thing together. The catch is honest and simple: none of this is cheap, and once you leave Old Town, you are driving.