Illuminated tent at Plaza de Mulas base camp, Aconcagua 6962m, highest peak in South America, Aconcagua Provincial Park, Andes mountains, Argentina, South America

Climbing expedition leaving base camp on Mount McKinley, 6194m, Denali National Park, Alaska, United States of America, North America

British Base and Post Office, Port Lockroy, Antarctic Peninsula, Antarctica, Polar Regions

Trekkers make their way along an alternative route via Photse to Everest Base Camp, Himalayas, Nepal, Asia

Adult black-legged kittiwakes (Rissa tridactyla) feeding at the base of a glacier in the Svalbard Archipelago, Norway, Arctic, Europe

Adult black-legged kittiwakes (Rissa tridactyla) feeding at the base of a glacier in the Svalbard Archipelago, Norway, Arctic, Europe

View signpost at Base Presidente Eduardo Frei Montalva, Antarctica, Southern Ocean, Polar Regions

Views of Base Presidente Eduardo Frei Montalva, Antarctica, Southern Ocean, Polar Regions

Views of Base Presidente Eduardo Frei Montalva, Antarctica, Southern Ocean, Polar Regions

Views of Base Presidente Eduardo Frei Montalva, Antarctica, Southern Ocean, Polar Regions

Views of Base Presidente Eduardo Frei Montalva, Antarctica, Southern Ocean, Polar Regions

Views of the Catholic church at the Chilean research base Presidente Eduardo Frei Montalva, Antarctica, Southern Ocean, Polar Regions

Views of the Chilean inactive research base Gonzalez Videla on Waterboat Point in Paradise Bay, Antarctica, Polar Regions

View of the Argentine base Almirante Brown, named after Guillermo Brown of the Argentine Navy, Paradise Bay, Antarctica, Polar Regions

British Antarctic Survey (BAS) research plane landing at the Chilean Research base Frei on King George Island, Antarctica, Polar Regions

View of the Argentine base Almirante Brown, named after Guillermo Brown of the Argentine Navy, Paradise Bay, Antarctica, Polar Regions

Views of the Chilean research base Presidente Eduardo Frei Montalva, Antarctica, Southern Ocean, Polar Regions

British Antarctic Survey (BAS) research plane landing at the Chilean Research base Frei on King George Island, Antarctica, Polar Regions

Views of the Chilean research base Presidente Eduardo Frei Montalva, Antarctica, Southern Ocean, Polar Regions

View of the Argentine base Almirante Brown, named after Guillermo Brown of the Argentine Navy, Paradise Bay, Antarctica, Polar Regions

Views of the Chilean inactive research base Gonzalez Videla on Waterboat Point in Paradise Bay, Antarctica, Polar Regions

Tent at Plaza de Mulas base camp, Aconcagua 6962m, highest peak in the western hemisphere, Aconcagua Provincial Park, Andes mountains, Argentina, South America

Tent at Plaza de Mulas base camp, Aconcagua 6962m, highest peak in the western hemisphere, Aconcagua Provincial Park, Andes mountains, Argentina, South America

Amundsen's base, scientific base, once a coal mine, Ny Alesund, Svalbard, Arctic, Norway, Scandinavia, Europe

Amundsen's base, airship expedition, Ny Alesund, Svalbard, Arctic, Norway, Scandinavia, Europe

High Mountain Rangers Tom Ditola and David Weber are taking a rest on the West Rib on Mount McKinley, Alaska. Mount Hunter in the background. They are above the clouds in blue sky and the sun is shining. Mount McKinley, native name Denali, is the highest mountain peak in North America, with a summit elevation of 20,321 feet (6,194 m) above sea level. At some 18,000 feet (5,500 m), the base-to-peak rise is considered the largest of any mountain situated entirely above sea level. Measured by topographic prominence, it is the third most prominent peak after Mount Everest and Aconcagua. Located in the Alaska Range in the interior of the U.S. state of Alaska, McKinley is the centerpiece of Denali National Park and Preserve. Every climbing season High Mountain Rangers of the Denali National Park Service are called to help climbers in need. If possible the patient is brought down to base camp on foot, only in life threatening conditions a helicopter is called to evacuate the patient to a hospital in Anchorage.

Mountain ranger Brian Scheele on this way to Windy Corner on Mount McKinley, also know as Denali, in Alaska. He is pulling a sled, that together with his heavy backpack is containing all the gear like tents, clothing and food. Every climbing season High Mountain Rangers of the Denali National Park Service are called to help climbers in need. If possible the patient is brought down to Basecamp on foot, only in life threatening conditions a helicopter is called to evacuate the patient to a hospital in Anchorage. Mount McKinley, native name Denali, is the highest mountain peak in North America, with a summit elevation of 20,321 feet (6,194 m) above sea level. At some 18,000 feet (5,500 m), the base-to-peak rise is considered the largest of any mountain situated entirely above sea level. Measured by topographic prominence, it is the third most prominent peak after Mount Everest and Aconcagua. Located in the Alaska Range in the interior of the U.S. state of Alaska, McKinley is the centerpiece of Denali National Park and Preserve.

Night scene of a dining tent at the Everest Base Camp. The summit of Everest is blocked by part of the ridge that extends out on the left, while Nupste can be seen on the right of the picture. The infamous Khumbu ice fall can be seen as the rubble that pours out in the middle of the picture, Nepal

Mountaineers climbing up the Khumbu Icefall on the route up Everest, Everest Base Camp, Khumbu, Nepal

Mountaineers climbing up the Khumbu Icefall on the route up Everest, Everest Base Camp, Khumbu, Nepal

Mountaineers climbing up the Khumbu Icefall on the route up Everest, Everest Base Camp, Khumbu, Nepal

A night scene of the Everest Base Camp, where climbers call this home for more than 2 months. They use the site as a base to move up to higher camps and also rest during days of non climbing, Nepal

Mountaineers climbing up the Khumbu Icefall on the route up Everest, Everest Base Camp, Khumbu, Nepal

Mountaineers climbing up the Khumbu Icefall on the route up Everest, Everest Base Camp, Khumbu, Nepal

A trekker stands over the Khumbu Glacier in Everest Base Camp.

Katy Holm sorts gear at the base Cerro Pollone in Argentine Patagonia. January 2005

Snowboarders Touring Out Of Base Camp In Canada

Mountaineers Are At The Base Of A Steep Wall On Denali, Alaska

Climbing legend Patxi Usobiaga at the base of El Pati crag, Siurana, Spain.

Two mountaineers at their base camp in rugged terrain.

Man sitting in base camp tent, Everest, Khumbu glacier, Nepal, Everest, Khumbu glacier, Nepal

The expeditionaries bound for Cap Prud'Homme and Dumont d'Urville, in front of the Basler that will take them there. It's worth noting that some of them are wearing the blue garment normally worn for Concordia: this is because it's warmer and contains more down, which is no luxury at the start of the summer season. A matter of habit and personal preference. The buildings of the Mario Zucchelli base can be seen in the background. Terra Nova Bay, Victoria Land, Antarctica

A German BGR helicopter used in Terre Victoria to transport geologists to specific research points. These are one-off scientific programs, involving the collaboration of several countries, in this case Germany and Italy. The Germans set up a base camp several dozen kilometers from the Italian Mario Zucchelli station, using Italian logistical resources such as the Laura Bassi icebreaker to transport the helicopter, the equipment needed to set up the base camp, scientific equipment and, of course, personnel. All of this was delivered to the Mario Zucchelli station for onward transport by helicopter to the search site. Victoria Land, Antarctica

A Lockheed C-130 Hercules on loan from the Italian Air Force for logistics operations between Christchurch;New Zealand) and the Mario Zucchelli base. Although military activities are strictly forbidden in Antarctic territory by the Treaty of Madrid, polar-operating countries frequently use the skills and equipment of their armies for polar logistics. Victoria Land, Antarctica

The airbus A320 landed on the pack ice of Terra Nova Bay, where the Mario Zucchelli base is located. Beneath its wheels lay 1.3m of ice and 300m of ocean. Victoria land, Antarctica

The Basler, stationed on the Terra Nova Bay ice floe in front of the Mario Zucchelli base. The mechanics take advantage of a rare lull to carry out routine maintenance. The aircraft is strapped to the ground. A squall arrives from the left. Victoria Land, Antarctica

A few weeks after the start of the summer campaign, the winterers who have just spent 14 months at Concordia return home. They take off from Concordia station aboard the Basler;photo), bound for Mario Zucchelli or Dumont d'Urville. Most of them make a sign indicating the village or town where they live, and the distance to Concordia. Concordia Antarctic Base