Guardian of the Mangroves – Overall Winner. Tanya Houppermans, Cuba. A curious American crocodile (Crocodylus acutus) swims right up to Tanya, at Gardens of the Queen (Jardines De La Reina), an archipelago off the coast of Cuba. It has been strictly protected since 1996, and is one of the most untouched marine ecosystems in the world. ‍ “The healthy population of American crocodiles is down to the pristine condition of the mangroves and I wanted to capture close ups of this gentle giant in its natural habitat. I hope this image can illustrate that protecting areas like this is so critical”. (Photo by Tanya Griffin Houppermans/Mangrove Photographer of the Year)

Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)

With their affinity for hunting, sneaking, and hidden blade-like retractable claw, cats are really the assassins of the animal world. They're not as intimidating when they're kittens dressed up as assassins from the upcoming Assassin's Creed Unity, but what they lack in deadliness they more than make up for in cuteness. YouTube user Mr.TVCow posted the video, in which four hooded kittens hunt down a french soldier, much like like in a number of trailers for Assassin's Creed Unity. They use their eagle vision ability, parkour after their target, and perform lethal aerial assassinations, and yes, it's as unbearably adorable as it sounds.

Iraq's second largest city, Mosul, is locked under the rule of extremists from the Islamic State group trying to purge it of everything they see as contradicting their stark vision of Islam. A trove of photographs now housed at the Library of Congress offers a glimpse of a different Mosul – before wars, insurgency, sectarian strife and now radicals' rule. The scenes were taken in the autumn of 1932 by staff from the American Colony Photo Department during a visit to Iraq at the end of the British mandate. (Photo by AP Photo)

This deviantART artist Wood-Splitter-Lee creates her own animal sculptures without the use of any dead carcasses. The basis of each animal's shape is made out of materials such as wood, clay and chicken wire, and is then wrapped up in a soft padding. On top of that, she adds imitation fur that she hand dyes and as many details and decorative elements as she sees fit. The result are truly one-of-a-kind fantasy creatures.

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.

A daredevil photographer is determined to capture London in a whole new light – by scaling the city’s many rooftops. Jacob Riglin, from Richmond Upon Thames, photographs the nation's capital from above – hanging from scaffolding, dangling his legs over the edge of buildings and looking down from perilous heights. Such images have gained the photographer, 20, an incredible fan base on Instagram, which has seen his follower count rise to more than 150,000. He said, “I had always been interested climbing and getting that adrenaline rush from feeling on top of the world”. Here: Jacob looking out to the London skyline. (Photo by Jacob Riglin/Caters News)

Christian Balderosdasco, 31, is being pulled up a mud pit after diving for 3 hours to look for gold on March 22, 2017 in Paracale, Philippines. Apart from tunneling and sifting sand, locals dive down murky swamps with the aid of a compressor with air flowing in a small tube for breathing, as they blindly swim under the mud for up to four hours to look for tiny rocks containing gold particles. For decades, local residents at Paracale town work in hazardous conditions scavenging under the earth and diving into tunnels filled with mud using only makeshift tools to mine for gold, often placing their health and lives at risk. (Photo by Jes Aznar/Getty Images)