Superior Bathhouse Brewery: The only brewery inside a US national park, Superior Bathhouse Brewery serves up craft beer and pub fare in a converted bathhouse in Arkansas' Hot Springs National Park. The brewery usually has around 18 beers on tap, all of which are brewed on-site using the same thermal waters that give this national park its name. It’s the perfect place to stop for a beer—or a full meal—after a day of pampering at the spas along the park’s Bathhouse Row.

Stehekin: On the northern headwaters of Lake Chelan in Washington State's North Cascades National Park, the community of Stehekin is among the most remote settlements in the lower 48. In fact, the only way to get to the town is by hiking for around 23 miles (37 kilometers), chartering a private float plane, or taking a boat from the city of Chelan, a few hours’ ride down the lake. Most people come in the summer to hike through old-growth forests and fish in Lake Chelan’s crystalline waters.

Brooks Camp: If you've ever seen videos of brown bears standing on the edge of a small waterfalls attempting to catch fish with their mouths or paws, the chances are high that you’ve caught a glimpse of Brooks Camp in Alaska’s Katmai National Park and Preserve. Every summer, large groups of these furry creatures descend on Brooks River to take advantage of the annual salmon run, which visitors can watch from the safety of viewing platforms.

Fruit Orchards: Although Capitol Reef National Park in Utah is primarily dominated by desert landscapes, it does have a lush side. A few minutes’ drive from the visitor center will take you to one of its historic orchards, which were largely planted toward the end of the 19th century by Latter-Day Saint pioneers. These days, the orchards—which include apple, apricot, peach, and pear trees—are maintained by the National Parks Service. You can even pick fruit to take home.

Jamestown Glasshouse: Inside Colonial National Historic Park in Virginia, near one of the earliest English settlements in North America, the Jamestown Glasshouse is a reproduction of a 16th-century glasshouse where residents took their first stab at manufacturing glass in America. You can see old furnaces that were excavated from the area in the 1940s, watch costumed interpreters create various wares out of glass, or even pick up some newer glass creations at the on-site gift shop.

Cliff Palace: Mesa Verde National Park in Colorado is known for its well-preserved cliff dwellings, many of which are believed to date back to the late 13th century. The largest and most remarkable of these is Cliff Palace, which reportedly housed around 100 people in its 150 rooms. See it by taking a tour of the park that includes a drive along Cliff Palace Loop Road, or sign up for a ranger-led tour that will allow you to climb up ladders and into some of the rooms.

Ptarmigan Tunnel: While many visitors to Glacier National Park in Montana stick to driving, intrepid hikers who explore on foot can admire gorgeous views and gain access to parts of the park that few get to see. One of Glacier's more curious attractions is the Ptarmigan Tunnel. In the 1930s, this roughly 250-foot (76-meter) tunnel helped hikers gain easier access to the park and its backcountry chalets; today, it serves hikers who want to admire the views of the Belly River Valley.

B Reactor: In the early 1940s, the US Government set up the Hanford Nuclear Reservation, a secret site in rural Washington, in order to produce plutonium to use in the first atomic bombs. The site was decommissioned in 1989, and later protected as part of the Manhattan Project National Historical Park. While most of the Hanford site is closed to the public, you can visit the B Reactor and some of the pre-WWII sites in the area on tours.

Fort Jefferson: Off the coast of Key West, in Florida’s Dry Tortugas National Park, the massive Fort Jefferson is one of the largest 19th-century forts in the US. It occupies most of Garden Key, the second-largest island in the park, and is open to visitors who want to explore its ramparts (or snorkel off of its shores). While it has a small number of public campsites, reservations go quickly, so people prefer to visit on a day tour instead.