Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

A pilgrim prays at Mount Al-Noor, where Muslims believe Prophet Mohammad received the first words of the Koran through Gabriel in the Hera cave, ahead of the annual haj pilgrimage in the holy city of Mecca, Saudi Arabia September 7, 2016. (Photo by Ahmed Jadallah/Reuters)

The winners of The London’s Natural History Museum's prestigious Wildlife Photographer of the Year for 2013 have finally been unveiled. Selected from almost 43,000 entries from 96 countries, the winners offer a glimpse of the stunning array of natural beauty on our planet. Photo: Canada: “Lucky pounce”. “Anticipating the pounce – that was the hardest part”, says Connor, who had come to Yellowstone National Park, Wyoming, USA, in search of wildlife as much as the spectacular landscape. He had found this fox, his first ever, on his last day in the park. It was so absorbed in hunting that Connor had plenty of time to get out of the car and settle behind a rock. It quartered the grassland, back and forth, and then started staring intently at a patch of ground, giving Connor just enough warning of the action to come. When it sprung up, Connor got his shot. And when it landed, the fox got his mouse. (Photo by Connor Stefanison/Wildlife Photographer of the Year 2013)

Tokyo Rainbow Pride 2015, at Yoyogi park-Shibuya, on April 26, 2015. Some 3,000 lesbian, gay, bisexual and transgender people paraded through Tokyo’s Shibuya district Sunday afternoon to demonstrate their hope that Japanese society will continue to forge ahead with recent moves to embrace equality and diversity. In a nation where prejudice against sexual minorities persists, the annual Tokyo Rainbow Pride parade has sought to counter the trend by openly spotlighting LGBT residents and spreading their voices. But this year, LGBT participants and proponents seemed particularly joyous, emboldened by what they see as a blossoming of LGBT-friendly moves by municipalities and companies. (Photo by Yoshiaki Miura)

The Costa Verde hotel. It is a fully outfitted two bedroom, Boeing 727 suite in Costa Rica. Located within tropical rainforest, Hotel Costa Verde’s rather unusual fuselage suite consists of a refurbished vintage 1965 Boeing 727 airframe. The aircraft was part of South-Africa Air in her previous life. Sitting atop a 50-foot pedestal just beyond a majestic national park, the remodelled jumbo jet’s interior is entirely Costa Rican teak panelling with Indonesian teak furniture and also features a private entrance up a river rock.

“Wombats are Australian marsupials; they are short-legged, muscular quadrupeds, approximately 1 metre (39 in) in length with a short, stubby tail. They are adaptable in their habitat tolerances, and are found in forested, mountainous, and heathland areas of south-eastern Australia, including Tasmania, as well as an isolated patch of about 300 ha in Epping Forest National Park in central Queensland”. – Wikipedia

Photo: “Abdul”, a baby Common Wombat, is one of the marsupials on show during the spring baby boom at Taronga Zoo September 1, 2005 in Sydney, Australia. “Abdul” was orphaned when his mother was killed by a car. (Photo by Mark Nolan/Getty Images)

Elephant fights off hyenas to save baby. “This is the incredible moment an elephant came to the rescue of one of its babies being attacked by a pack of hyenas. The elephant is seen charging at the hyenas to ward them off its offspring. The photos were captured by American photographer Jayesh Mehta, 47, in the Savuti region of the Chobe National Park in Botswana”. Photo: The elephant is seen charging at the hyenas to ward them off its offspring. (Photo by Jayesh Mehta/Caters News)

Moraine Lake is a glacially-fed lake in Banff National Park, 14 kilometres (8.7 mi) outside the Village of Lake Louise, Alberta, Canada. It is situated in the Valley of the Ten Peaks, at an elevation of approximately 6,183 feet (1,885 m). The lake has a surface area of .5 square kilometres (0.19 sq mi). The lake, being glacially fed, does not reach its crest until mid to late June. When it is full, it reflects a distinct shade of blue. The colour is due to the refraction of light off the rock flour deposited in the lake on a continual basis.