On the western side of Mount Hood lies the longest glacier cave system in the contiguous United States. In 2012, these caves were mapped to a combined length of 7,166.8 feet by cave explorers Brent McGregor and Eddy Cartaya. Currently, the total passage length is hundreds of feet less. Glaciers are frozen rivers; they are always moving and changing... (Photo and caption by Josh Hydeman)

From towering elephants to tiny insects, photographers will be offering a rare insight into the natural world at this year’s Wildscreen Photography Festival 2014. The festival, formerly known as WildPhotos, is the UK’s largest wildlife photography show. The Wildscreen Photography Festival 2014 will be taking place between 24-26 October at London’s Royal Geographical Society. (Photo by Sam Hobson/Wildscreen Photography Festival 2014)

Ellora is an archaeological site, 29 km (18 mi) North-West of the city of Aurangabad in the Indian state of Maharashtra built by the Rashtrakuta dynasty. It is also known as Elapura (in the Rashtrakuta literature-Kannada).

“Today, we take photography for granted. Anyone can take a photograph simply by pressing a button. Yet, it was not always so simple. The invention of photography was announced in 1839, but during its first fifty years taking a photograph was a complicated and expensive business. In 1888, all this was to change following the appearance of a camera that was to revolutionize photography. Popular photography can properly be said to have started 120 years ago with the introduction of the Kodak”. – The UK National Media Museum. Photo: Two men on the deck of a ship, about 1890. (Photo by Collection of National Media Museum/Kodak Museum)

In this February 2, 2014 photo, people take pictures inside a cave at Apostle Islands National Lakeshore in northern Wisconsin, which has been transformed into a dazzling display of ice sculptures by the arctic siege gripping the Upper Midwest. (Photo by Brian Peterson/AP Photo/Minneapolis Star Tribune)

Fog hangs between pine trees in a forest near Neubrueck, eastern Germany, on November 20, 2012. Meteorologists forecast cloudy sky and temperatures around 5 degrees Celsius for the region. (Photo by Patrick Pleul/AFP Photo)

A boat sails behind a woman looking through binoculars as she sits on a cliff on a sunny day in Sydney, Australia, May 29, 2016. (Photo by David Gray/Reuters)

Wildlife photographer Danté Fenolio has headed into areas untouched by sunlight – deep seas, caves and underground – and found creatures that are exploding with colour. Here: The golden harlequin toad has vanished from the wild, and only a small number live on in captivity. A fungus caused them, and many other amphibians, to die out in their home in Central America. (Photo by Danté Fenolio/The Guardian/Johns Hopkins University Press)