Biafo Glacier is located in the Karakoram Mountain Range (sometimes considered part of the Himalayas, where glaciers are retreating at an alarming rate). Tourists looking for a challenge can hike on the remote glacier for several days to reach the ten-mile wide Snow Lake. Along the way, they are treated to sights of rare flora and fauna, as well as to the mountain peaks of Pakistan.

Located 48 miles from the Argentine town of El Calafate, the Perito Moreno Glacier is an exception in the area: Of the 50 or so southern Patagonian glaciers, only three are advancing, and Perito Moreno is one of them. Three viewing areas allow tourists to get safely up close and personal with the mass of ice. Lucky visitors witness huge chunks of ice breaking from the glacier and plummeting into Lake Argentino.

Alaska is home to more than 100,000 glaciers. More than 2,000 of these are substantial in size, says Bruce Molnia, a scientist at the U.S. Geological Survey who has been studying glaciers and other topics related to global water supply for more than 40 years. Glacier National Park is one of the best places to view a number of the large glaciers. Glacier Bay Lodge is the only accommodation within the park, and from it, visitors travel by boat through the bay, seeing numerous major glaciers in one day, including the spectacularly massive Margerie and Grand Pacific.

Resting at the foot of Austria's tallest mountain, the Pasterze Glacier is today about five miles long—the largest of Austria's 925 glaciers. However, Pasterze could lose up to 60 percent of its mass by 2100. For now, though, visitors can take in a magnificent view of both glacier and mountain by taking the Grossglocknerstrasse mountain road (open only in summer) to Kaiser-Frans-Josefs-Hohe, which maintains a large visitors center.

Anyone who ever wondered how Iceland got its name would likely find the answer in the fact that the country's largest glacier alone covers more than eight percent of the country. Near the Vatnajökull Glacier's center, several active volcanoes make for a contrasting landscape. For example, visitors can visit hot springs located within the glacier's ice caves.

China's Yulong Glacier has been receding steadily since the early 1980s, but it is still one of the most popular attractions in the Yunnan Province. It's not necessarily easy visiting the glacier—the high altitude of the final climb to the observation deck leaves many visitors gasping for air. Some even make the climb with small oxygen bottles.

Although sibling glaciers Fox and Franz Josef retreated for much of the 20th century, they are currently advancing, thanks to the area's recent heavy precipitation. They are also unique among the world's glaciers in that they extend down the mountains and into a temperate rainforest. Visitors can experience the glaciers in any number of ways, including by helicopter and on foot, where it is often possible to explore the many tunnels and crevasses.

Part of the Canadian Rockies' Columbia Icefield, a system of glaciers that straddles the Continental Divide, the Athabasca Glacier has already lost half its volume and continues to recede. Still, it is currently almost four miles long. Although the most popular glacier in North America for tourists, it is also one of the more dangerous—visitors are cautioned not to set foot on the ice without a guide.

Tourists are heading to Antarctica's countless mountains, bays and glaciers in record numbers—nearly 35,000 are expected to visit this year, up from barely 10,000 a decade ago. Ironically, it is the melting ice brought on by global warming that is allowing these increases. The International Association of Antarctica Tour Operators was formed in 1991 with the purpose of establishing guidelines for environmentally responsible tourism to the continent.