A new book published by the UK Natural History Museum showcases some of the most memorable underwater photographs taken over the last few decades in its annual wildlife photographer of the year competition. Here: Giant gathering by Tony Wu. “The first indication that something extraordinary was going on were the blows, huge numbers of them – the exhalations of huge numbers of whales. Entering the water, the photographer witnessed an extraordinary scene”. (Photo by Tony Wu/Unforgettable Underwater Photography/NHM)

Members of South Korean girl group Gfriend rehearse in Seoul December 23, 2014. Thousands of Korean children dream of becoming household names like rapper Psy, whose 2012 “Gangnam Style” video was a global YouTube hit, often putting up with punishing schedules in the hope of one day making it big in the music industry. A recent survey of pre-teens showed that 21 percent of respondents wanted to be K-pop (Korean pop) stars when they grow up, the most popular career choice. (Photo by Kim Hong-Ji/Reuters)

Exhilaration beyond imaginable, intense concentration on a single point, and complete freedom of soul – all these things very accurately describe the art of highlining. Highlining is a branch of a new sport called slacklining, which involves walking on special webbing secured between two points. Andi Lewis is one of the most famous slackliners in the world, particularly due to his performance during Superbowl Halftime Show in 2012. He never fails to surprise people with an amazing stunt or a project. This time he and his friends have created a completely incredible hand-knitted hammock located hundreds of feet above the ground. Just getting to this hammock requires immense skills and bravery. But once you’re finally there, you can rest a while, before mustering up the courage to go back across a narrow line with nothing but thin air beneath your feet.

Shi'ite fighters launch a rocket during clashes with Islamic State militants on the outskirts of al-Alam March 8, 2015. Thaier Al-Sudani: “It was me and a few other Iraqi journalists working for local outlets. We went to the frontlines in coordination with the Iraqi government forces and supporting militias. The press officer would come in the morning and take us to the frontline in a convoy. Whenever an area was won from Islamic State, the fighters would chant and pray and show victory signs. Most of the areas we were in didn't have residents, so after the battle they would resemble ghost towns; nothing but burnt cars and charred bodies of Islamic State fighters. Al-Alam was an exception as it had some residents who chanted for the government forces after their victory”. (Photo by Thaier Al-Sudani/Reuters)

Turkish artist Nezaket Ekici performs a live art performance entitled 'Emotion in Motion' on the first day of Art Basel 2015, Hong Kong, China, 13 March 2015. The Hong Kong show of Art Basel features 233 galleries from 37 countries and territories, presenting works ranging from the Modern period of the early 20th century to the most contemporary artists of today, according to the official press release. (Photo by Alex Hofford/EPA)

This photo taken on April 16, 2014 shows ethnic Kayan women wearing traditional clothes and bronze rings around tbeir neck in Panpet village, Demoso township in Kayah state, eastern Myanmar. Some ethnic Kayan women, also known as Padaung, begin wearing the bronze rings on their neck and legs from a young age. Usually they start wearing six to ten rings when they are five to ten-years-old and then they put on one more ring a year for years after then. (Photo by Ye Aung Thu/AFP Photo)

“This is the terrifying moment a diver came head to head with a shark as it swims inches away snatching a bite for dinner. The close encounter, captured off Bimini Island in the Bahamas, shows the hammerhead approaching diver Eli Martinez who bravely stands his ground as the giant beast approaches. Eli, free diving outside of a protective cage, carefully handled the sea creature despite its menacing razor-sharp teeth – but admitted they are extremely shy and need a lot of work to allow divers close to them. After multiple trips and hours of diving nearby they finally got used to Eli in January this year – hammerheads regularly visit these waters during the winter season”. – Caters News. Photo: Eli Martinez with hammerhead shark. (Photo by J. P. Zegarra/Caters News)

“This quirky collection of photos proves that a little imagination is the key to a good a picture. By simply using a collection of keys and a strip of chalk, photographer, Stanislav Aristov, 32, is able to re-create everyday scenes and objects. Stanislav wanted to show that even the simplest of items can help change your view on the world. After acquiring a large selection of keys from friends and family as well as local charity shops, Stanislav then went about scrawling anything from a key shaped rain drops to a key-eyed crab”. – Caters News. Photo: A man walking his dog in a park made using chalk and keys. (Photo by Stanislav Aristov/Caters News)