A cenote is a natural phenomenon, a sinkhole in the Earth’s surface. The Yucatan Peninsula in Mexico has an estimated 7,000 cenotes because it is primarily made up of porous limestone. For millions of years, rainfall slowly ate away at the limestone and a huge system of underground caves and caverns was formed. Many filled with water from rain or from the underground water table. When the roof of a water filled cave collapses, a cenote is born. The water found in a cenote may be fresh water, salt water, or both. Structurally it may be completely open, like a lake, almost completely closed with just a small opening at the top, or somewhere in between.

Vanessa, thirty-five, had three children with an abusive husband. She “lost her mind, started doing heroin”, after losing the children, who were taken away and given to her mother. The drugs led to homelessness and prostitution. She grew up on Arthur Avenue in the Bronx, but now spends her time in Hunts Point, “trying to survive everyday. Just doing whatever it takes”.

A Dancer, dressed with the traditional Yi costume, waits to perform at the Torch Festival, in Xichang, China's Sichuan province on July 27, 2016. As a result of fast urbanisation in the rural area of China Like Lienchang prefecture, the traditional costume is fading away for the Yi people in daily life. (Photo by Fred Dufour/AFP Photo)

Have you ever heard of a phenomenon called the Uncanny Valley? Illustrations created by Swiss illustrator Christo Dagorov show how horrible something may look when it’s a hair’s breadth away from looking human. In his illustrations he combined the shape of human lips with trees, buildings, and even human bodies, making it look from a distance as if the lips were horribly deformed by some unknown disease. However, after a while you make out the shapes, yet the feeling of uneasiness remains, making you shiver from unsuppressable disgust. (Photo by Christo Dagorov)

Here are the bravest of the brave in 2016. Weve gathered some of the finest images showing daredevils taking their lives into their own hands and going to the very brink this year. Whether they are perched hundreds of feet up on a high wire, courageously clinging to a rockface or taking on a volcano, these adventurers take the breath away. Here: Morgane Choquet and Samuel Cobb relax in a vertical campsite on the slopes of El Capitan, Yosemite National Park. (Photo by Alexandre Eggermont/Caters News)

A worker walks beside the ocean liner Queen Mary II in a dock at Blohm&Voss shipyard in Hamburg, Germany, June 14, 2016. The mighty Queen Mary 2 is just days away from setting sail after the most expensive refurbishment of any ship in history. Tens of millions of pounds have been spent on the 151,200-tonne ship as 2,500 workers complete the month-long major interior overhaul. (Photo by Fabian Bimmer/Reuters)

Andrew Ling's inspiring photographs showcase the splendor of the natural world, using people to highlight the beauty and scale of these epic landscapes. Each image features a person photographed from hundreds of feet away, seemingly insignificant in comparison to the breathtaking landscape that surrounds them – whether beneath gushing waterfalls, under millions of glittering stars or atop of gigantic cliffs. Andrew, 22, said, “I hope these images will help remind people how beautiful the world we live in is”. Here: Second Beach, La Push, Washington, March, 2015. (Photo by Andrew Ling/Caters News)