A man stands by an installation depicting “2019” in the Red Square in Moscow, Russia on December 17, 2018. (Photo by Maxim Shemetov/Reuters)

Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)

Respect, Kronotsky nature reserve, Russia. The photographer’s cat, Ryska – her name means little lynx in Russian – stands outside their cabin and with aggressive posturing warns off a fox. In winter, foxes would regularly visit the cabin searching for food. If one peered in at the window, possible when the snow was deep, Ryska would sit on the other side, fur raised, and growl. When outside, she would hold her ground. The foxes were not always frightened and so encounters could be a sort of dance. (Photo by Igor Shpilenok/Unforgettable Behaviour/NHM)

Among the fish populations that could be harmed by the Xayaburi dam in Laos is the critically endangered Mekong giant catfish, considered by the Guinness Book of World Records to be the world’s largest freshwater fish. The fish, which grows to 650 pounds and about 10 feet long, is only found in the Mekong River. It is migratory, moving between downstream habitats in Cambodia upstream to northern Thailand and Laos each year to spawn. Some experts fear the Xayaburi dam could block the migration and drive the giant catfish to extinction. (Photo by Courtesy of Zeb Hogan/University of Nevada, Reno)

A dead sperm whale is seen on the beach on March 18, 2012 in Yancheng, Jiangsu Province of China. Four giant sperm whales, which were found beached on the beach of Xintan Salt Field on Friday, died on Saturday despite rescue efforts. (Photo by ChinaFotoPress)

Kahuna, an injured loggerhead turtle, returns to the ocean after years of rehabilitation. It has been two years since Kahuna, a 209-pond loggerhead turtle, was rescued from the wild by biologists at FPL’s St. Lucie Power. Half of one of her flippers had been sliced off, and the other flipper was badly injured. On top of that, she had severe bone infection doctors tried for months to cure with antibiotics, only to have it come back once they stopped the medicine.

Photo: Kahuna is kept calm and steady on the gurney by staff and volunteers.

In this November 17, 2014 photo, Pancho, a domesticated huitia, confronts a camera, in Bainoa, Cuba. With their rope-like, dark tails, long front teeth, and whiskers that appear to be vibrating, huitias look like giant rats. They measure nearly a foot long (about 30 centimeters), with the largest ones weighing in bigger than a small dog. (Photo by Ramon Espinosa/AP Photo)

Photographer Mihaela Noroc travelled the world from Ethiopia to the US and from Guatemala to France in search of natural and authentic beauty. She introduces some of the inspiring women she met on her journey. Here: Ecuador. “More and more tribes of Amazonia are starting to adopt modern clothes for everyday life. But they are still keeping their traditional clothes for important events. I photographed this young woman in her wedding outfit”. (Photo by Mihaela Noroc/The Guardian)