5 Best Sights in Aspen and the Roaring Fork Valley, Colorado

Newer and more relaxing than its famed sibling across town, Iron Mountain Hot Springs is geared to adults looking for a peaceful retreat. Seventeen mineral pools with views of the Colorado River and Mt. Sopris are scattered across the hilltop; temperatures vary from 98°F to 108°F. A large family pool, heated to 94°F, encourages young children to stay out of the soaking spas, and soothing music drowns out much of the noise from the nearby kids' area. On-site bars offer a variety of beer and wine for sipping at the pools, and the contemporary locker rooms maintain the property's spa–like atmosphere. In summer 2023, a new adults–only area complete with two large pools with waterfalls and eight riverside pools lined with relaxation pebbles opened to visitors over 21. Reservations are required and visits are limited to three hours.

It took the Colorado River a half-billion years to carve the deep granite, limestone, and quartzite gullies—buff-tint walls brilliantly streaked with lavender, rose, and ivory—of this 16-mile-long canyon. Then, man stepped in, seeking a more direct route west. In 1992, the costly work on I–70 through the canyon east of Glenwood Springs was completed, with much of the expense attributable to the effort to preserve the landscape. When contractors blasted cliff faces, for example, they stained the exposed rock to simulate nature's weathering. Bike the canyon on a paved, riverside recreation path, hike to the steep (but worth it) trail to Hanging Lake or try to focus on fishing or rafting the river with views of the canyon walls towering above.

Glenwood Springs is home to the Historic Fairy Caves (now part of the adventure park), whose subterranean caverns, grottoes, and labyrinths are truly a marvel of nature—the area was touted as the "Eighth Wonder of the World" when it opened to the public in the 1890s. The still-amazing caves are easily accessible year-round via the Glenwood Gondola, which offers a bird's-eye view of downtown, the Colorado River, and surrounding mountains. Choose from two different 40-minute walking tours of the caves, or opt for the crawl-on-your-belly "Wild Tour" spelunking adventure. For a second helping of adrenaline, try the gravity-powered alpine coaster that winds down 3,400 feet down the mountain; sail out over 1,300 feet above Glenwood Canyon on a giant swing; or drop, roll, and twist on the Defiance roller coaster that overhangs a cliff.

Even before the heyday of the adjacent Hotel Colorado, Western notables such as gunslinger Doc Holliday came to take advantage of the area's curative spring waters. The smaller pool at Glenwood Hot Springs is 100 feet long and maintained at 104°F. The larger is four times that size and contains more than a million gallons of constantly filtered water that is completely refilled every six hours and maintained at a soothing 90–93°F. Seasonal favorites include a children's area with a splash pad, fountain, waterslides, and an on-site pizza stand and café.

Part of the Yampah Spa and Salon, the hot springs vapor caves are a series of three underground, geothermal steam baths. Mineral-filled water from a natural hot spring runs about 125°F under the floors of one of the few known natural vapor caves in North America, creating steam temperatures of 110°F–112°F within the rock chambers, where there are marble benches for you to sit on while you inhale the steam. You can take a break in an adjacent cooling room or the upstairs solarium when you need it. Spa treatments are also available, including massages, body wraps, and private mineral baths. Reservations are required and visitors are limited to two hours.