Underwater photographer of the year – winner. Dancing Octopus by Gabriel Barathieu (France). Location: Island of Mayotte, off the coast of south-east Africa. “Balletic and malevolent”, one judge said of this octopus, hunting in a lagoon. Barathieu waited until spring tides when there was just 30cm of water on the flats and plenty of light in the shallows. (Photo by Gabriel Barathieu/UPY2017)

These frozen caves seem almost otherworldly as they daylight illuminates them. Matej Kriz’s shots reveal the beauty of the brilliant caves, but he’s also very aware of how deadly they can be. The photographer captured the amazing shots in the Vatnajokull National Park on the Breidamerkurjokull glacier tongue. Here: The ice caves, taken in the Vatnajokull National Park in Iceland, on November 11, 2017. (Photo by Matej Kriz/Caters News Agency)

A street cleaner demonstrates his martial arts skills in front of a closed shop near Beijing's Tiananmen Square September 2, 2015 as the capital prepares for tomorrow's parade. (Photo by Damir Sagolj/Reuters)

The Bahamas, the Commonwealth nation of hundreds of islands roughly the size of Connecticut and with population of just a bit over Anaheim, is known for its crystal waters and pristine beaches. This is possibly one of the world’s most beautiful havens of nature, yet people are coming here to see pigs. It is unclear when the pigs first appeared on Exuma Island or where they come from. There’s talk about a daring escape from a shipwreck, or sailors releasing the swine on purpose. In all probability, there were no pigs on this tropical paradise before European settlers came, so their mere presence is the work of human. The intriguing feat of nature, however, is that this population of pigs developed a fine aptitude for swimming. Here: “So you're on a boat in Bahamas and then this pig swims by begging for food”. (Photo and caption by Lisa Larsen/Public Domain)

With six-inch fangs and weighing in at 600lb, Saber and Janda are no ­ordinary house cats. Yet these huge Bengal tigers live in Janice Haley’s suburban garden and are treated like ordinary pets. They are fed by hand, get strokes and cuddles, and white male Saber goes to sleep sucking on her finger. Janice’s life changed 20 years ago when she spotted an advert for a tiger training course in her local paper – and two years later arrived home with her first cub. Then in 2002 she bought Janda, who is now 12. Photo: The pair are best of friends. (Photo by Ruaridh Connellan/Barcroft Media)

Krista Long began snapping pics of people sliding down a water slide after many visits to the local water park with her tween daughters. The result is an action-packed series that show emotions ranging, she says, “from pure joy to fear, in anticipation of the inevitable splash-down!” (Photo by Krista Long)

This year's Republican National Convention and Democratic National Convention both saw passionate delegates in outrageous costumes – but that's where the similarities mostly end. Reuters photographer Jim Young gives a look at what it's like to be on the convention floor and talks to the delegates who make the conventions memorable. (Photo by Jim Young/Reuters)