Are you struggling in the summer heat? Let’s flashback to December and take a mental stroll through the ice caves at Apostle Islands National Lakeshore in Wisconsin. Accessible by foot when Lake Superior freezes over – which doesn’t happen every year – the caves are like a palace decorated with hanging blue ice formations. It’s a very cool experience. Photo by Wan Shi (http://ift.tt/18oFfjl).

Acadia National Park in Maine is known for its sunrises. The park is one of the first places to see the sunrise in the U.S., but its sunsets are also stunning! Photographer James Kaiser captured this magical view from the top of Cadillac Mountain after a rainy day: “Even when things seem gloomy, conditions can quickly change. It’s one of nature’s most important lessons, and national parks help us appreciate it firsthand.” Photo courtesy of James Kaiser.

From the bottom of the deepest glacial fjord to the summit of its highest peak, Glacier Bay National Park & Preserve in Alaska encompasses some of our continent’s most amazing scenery and wilderness. Photographer David Canales explored this incredible park on a two-week kayak expedition. One day, he decided to hike up the east side of Lamplugh Glacier and captured this terrific view. Photo courtesy of David Canales.

A great blue heron enjoys an amazing sunset at Back Bay National Wildlife Refuge. Located on the southern coast of Virginia, Back Bay provides feeding and resting habitat for migratory birds. The refuge contains over 9,250 acres and is a great place for boating, biking and enjoying the beautiful views. Photo by Robert Merrill (http://ift.tt/18oFfjl).

Channel Islands National Park in California encompasses five remarkable islands and the dynamic ocean waters around them. Isolation over thousands of years has created unique animals, plants and archeological resources found nowhere else on Earth. And if that isn’t enough, the sunsets are amazing. Photo by Kurt Schuette (http://ift.tt/18oFfjl).

Organ Pipe Cactus National Monument in Arizona protects spectacular wilderness in the heart of the Sonoran Desert. The park is the only place in the United States where visitors can see large stands of organ pipe cacti, which can live to be more than 150 years old. Explore this Southwest gem with activities like hiking, camping, wildflower walks, scenic drives and night sky gazing. Sunset photo by Jim Dunham (http://ift.tt/18oFfjl).

Incredible sunsets are one of the many rewards of hiking along the Appalachian Trail, a national scenic trail that stretches from Georgia to Maine. Native to the Appalachian Mountains, rhododendrons bloom in this gorgeous photo that was taken along the trail near the Roan Highlands on the border of Tennessee and North Carolina. With so many great vistas to choose from, this scenic area is a favorite with day hikers and backpackers alike. Photo courtesy of Serge Skiba.

Red rocks and curving, swirling bluffs rise up out of the desert, creating a surreal landscape at Stud Horse Point. Part of Glen Canyon National Recreation Area, Stud Horse Point is a remote area near the Utah-Arizona border that’s worth the visit. On a tour of the Southwest with his buddies, Aron Cooperman drove through rain, wind and even some snow, made some wrong turns but they eventually found their way to the this spot. They stuck it out, rain clouds cleared and eventually, the sky started to have this incredible color explosion at sunset. Photo courtesy of Aron Cooperman.

Katmai National Park & Preserve in Alaska provides some of the few remaining unaltered habitats for bears. With about 2,200 brown bears in the park, scientists are able to study bears in their natural habitat, visitors are able to enjoy unparalleled viewing opportunities (from safe distances) and the bears are able to continue their life cycle largely undisturbed. Photo by Mike Clime (http://ift.tt/18oFfjl).

Rising nearly 5,000 feet above Yosemite Valley and 8,800 feet above sea level, Half Dome is a Yosemite National Park icon and a great challenge to many hikers. At least a 14-mile round trip through wilderness with an elevation gain of over 4,800 feet, this hike is not for the unprepared. Permits are required to reduce crowding – protect natural and cultural resources, and improve safety. But for those who make to the top, the view is indescribable. Photo by National Park Service.