These incredible caves are constantly on the move as the glacier inches towards Mendenhall Lake and changes shape along the way. The best way to access them is from the West Glacier Trail with the help of a guide. Above and Beyond Alaska leads hikes to the crevasses and caves of Mendenhall Glacier, and provides crampons and mountaineering gear.
One of the most popular attractions in Mount Baker-Snoqualmie National Forest, and only a short drive from Seattle, these caves are formed in a perennial pile of avalanche debris on the north face of Big Four Mountain which is kept from melting by the mountain’s shadow. Streams formed by the summer melt carve the caves out of the ice. Photos like this may make entering them seem enticing, but be warned: the caves are unstable and two people have been killed by falling ice there in recent years.
The largest glacier in France, the Mer de Glace lies on the slopes of Mont Blanc, Western Europe’s highest mountain. An “ice grotto,” complete with caves and ice sculptures, is carved out every year to allow visitors inside the glacier.
This glacier, in Westland National Park on New Zealand’s South Island, actually ends in a temperate rainforest, making it very easy to visit. You can hike right up to the edge, but to see the ever-changing formations and ice caves of its interior, your best bet would be a “helihike” by Fox Glacier Guides, which takes you to a remote site on the glacier via helicopter.
Thought to be the largest network of ice caves in the world, this underground cavern in the Austrian Alps translates as “world of ice giants” because of its huge size—around 30 miles—and the eerie formations that fill its “rooms.”
The show Breaking Bad may have made Albuquerque synonymous with “blue ice,” but a short drive west on I-40 can take you to a place where a different hue prevails. At Bandera Volcano in El Malpais National Monument, a 20-foot-thick layer of bright green ice lies at the bottom of a collapsed lava tube. Because the basalt walls insulate the cave even in the searing New Mexico summer, the temperature never gets above 32 degrees and water that flows into the cave freezes—with a layer of green algae on top.
This tiny town in western Greenland is so close to the island’s massive ice sheet—the second largest in the world after Antarctica’s—that you can actually drive to its edge. Caves formed by the summer melt abound here, and can be accessed with the help of tour operators. World of Greenland Arctic Circle offers two-day overnights on the ice cap, and Arctic Caving Adventure can take you deep in the tunnels and shafts formed by meltwater.
The third-largest ice cap in the world is in Patagonia, feeding dozens of glaciers in this national park. One of the best places to explore is Viedma Glacier, which flows into Viedma Lake near Mount Fitz Roy. Patagonia Aventura offers an “Ice Trek” tour on, and into, the deep blue ice.
A tourist attraction since the 1800s, this UNESCO World Heritage site in Slovak Karst country is filled with columns, domes and stalagmites, all made of ice. Open to visitors from May through September, temperatures in the nearly mile-long cave can get down to the 20s Fahrenheit, so bring a jacket.
Juneau isn’t the only place in Alaska with awe-inspiring glacial caves. Glaciers cover over 5,000 square miles of this park (which is the largest in the United States), and two of the most accessible are Root Glacier and Kennicott Glacier, both near the abandoned mining town of Kennecott. Operators leading tours into the caves include Alaska Denali Travel and St. Elias Alpine Guides.