At the beginning of the 20th century, Edward S. Curtis set out to document what he saw as a disappearing race: the Native American. From 1907 to 1930, Curtis took more than 2,000 photos of 80 tribes stretching from the Great Plains to the Pacific Northwest and Alaska. He then published and sold these photos, along with narrative text, in 20 volumes of work known as “The North American Indian”. It is one of the most significant collections of its kind, “probably the most important photographic document of its age and its topic,” said Jeffrey Garrett, associate university librarian for Special Libraries at Northwestern University. (Photo by Edward S. Curtis)

A burning flame and a broad expanse of water are among the few things which do not tire us with their beauty. However, while we have many sources of water around us, it is quite hard to marvel at a burning flame on a daily basis. Melissa Crisp is one of the few people who were able to subdue the element of fire. She is the person who is behind the design of the uniquely-shaped fire pits, which feature mystifying themes, including a pair of lovers, a fire on the rodeo arena, a forest fire, a fiery flower, and a number of others. Each of the fire pits entrances you, and it almost seems like the characters are alive, as the hot fire burns deep within the spheres, casting dancing shadows all around. (Photo by Melissa Crisp)

A dog sits in the shade of a mangrove tree as a woman uses a fork to dig for shellfish on the reef-mud flats of a lagoon located at South Tarawa in the central Pacific island nation of Kiribati May 23, 2013. Kiribati consists of a chain of 33 atolls and islands that stand just metres above sea level, spread over a huge expanse of otherwise empty ocean. With surrounding sea levels rising, Kiribati President Anote Tong has predicted his country will likely become uninhabitable in 30-60 years because of inundation and contamination of its freshwater supplies. (Photo by David Gray/Reuters)

Maratus is a spider genus of the Salticidae family (jumping spiders). These spiders are commonly referred to as peacock spiders due to their colorful abdominal flaps that they display during courtship. In at least one species, Maratus vespertilio, the expansion of the flaps also occurs during ritualised contests between males. All described species, except M. furvus, are endemic to Australia. (Photo by Jurgen Otto)

As you look at the set of pictures created by Tom Kondrat during his travels in Iceland, the first thing that comes to mind is the word “loneliness.” These pictures lead you to believe that Iceland is a desolate expanse of icy wasteland. You can almost imagine the strong wind howling in your ears, as it chills you straight to the bone. And as you’re walking down so beaten path, you’re all alone, with not a human soul for miles in any direction. This may prove unbearable for some, yet others find comfort in such places. With no one there to bother them and distract them from their thoughts, they can finally be at peace. (Photo by Tom Kondrat)

Floating on clear deep water and reflections near the cave entrance. Visitors can either bring their own kayaks or rent boats from the local community to paddle deep inside the cave and marvel at its wonders on March 2015 at Tham Khoun Ex, Laos. Tham Khoun Xe, commonly known as the Xe Bang Fai River Cave, in Laos, has over 15km of passages filled with awe-inspiring views and wide expanses of water. Photographer, John Spies, 59, captured scenes from the entrances of the huge underground river passages, intricate cave formations and views from a passage high above the water. The cave is formed by the Xe Bang Fai river, a major tributary of the Mekong and in the dry season can be traversed using inflatable kayaks. (Photo by John Spies/Barcroft Media/ABACAPress)

A Baby sumatran orangutan (Pongo abelii) plays around in a tree as they train at Sumatran Orangutan Conservation Programme's rehabilitation center on November 12, 2016 in Kuta Mbelin, North Sumatra, Indonesia. The Orangutans in Indonesia have been known to be on the verge of extinction as a result of deforestation and poaching. Found mostly in South-East Asia, where they live on the islands of Sumatra and Borneo, the endangered species continue to lose their habitat as a result of corporate expansion in a developing economy. Indonesia approved palm oil concessions on nearly 15 million acres of peatlands over the past years and thousands of square miles have been cleared for plantations, including the lowland areas that are the prime habitat for orangutans. (Photo by Ulet Ifansasti/Getty Images)

People in Kathmandu joke that the face mask has now become part of the national dress – an indispensable accessory in an effort to protect themselves from the dust. Nepal has the worst air quality in the world, according to the Environmental Performance Index. (Photo by Pete Pattisson/The Guardian)