Founded in 1989, the Icehotel in Swedish Lapland is built from the snow up each year, using ice from the local river. The rooms are designed by international artists and this year feature spacemen and an ice queen. The hotel has 35 suites, featuring ice carvings designed by 36 different artists from 17 countries. (Photo by Asaf Kliger/IceHotel/The Guardian)

A UFO enthusiast who found himself locked in the iconic Roswell museum has shared the pictures he took with aliens to pass the time. Chris Burton, from the U.K., had dreamed of visiting Roswell, N.M., since he was a child but was stunned when he found himself locked in the International UFO Museum and Research Center during a recent trip. The 42-year-old used the unique opportunity to get interactive with the usually out of bounds exhibits and set up some funny snaps with the extraterrestrials – posing for a beer with one alien and taking a nap with another. (Photo by Chris Burton/Caters News Agency)

A mother and her daughter paddle during a Stand Up Paddle (SUP) race of the Alpine Lakes Tour, on Europe's biggest underground lake, in St-Leonard, Switzerland, March 10, 2018. SUP is an offshoot of surfing that originated in Hawaii. Unlike traditional surfing where the rider sits until a wave comes, stand up paddle boarders stand on their boards and use a paddle to propel themselves through the water. (Photo by Denis Balibouse/Reuters)

The Tree Projects team spent 67 days documenting one eucalyptus regnans in the Styx valley of Tasmania. Using a combination of tree-climbing and elaborate arboreal rigging techniques, they produced an intimate portrait from an impossible perspective of one of the world’s largest individual flowering trees, which goes by several common names. These photos document the process that resulted in an extraordinary ultra high-definition photograph. Here: Haley nears the top of the tree. (Photo by Steven Pearce/The Tree Projects/The Guardian)

Tens of thousands of HIV positive prostitutes in the slums of Lagos to ensure a rapid spread of the epidemic. “If you arrive by car, you can smell the HIV virus outside”, joked my driver as we are on track to Badia a criminal slums of Lagos. Badia is a corruption of “Bad Area”. Nigerians have a lack of everything, except black humor. The poor West African country Nigeria, with a population of 140 million people, after India and South Africa the highest number of people with HIV / AIDS. (Photo by Ton Koene/Exclusivepix Media)

Warriors from the Suri tribe in Ethiopia still stage the savage “Donga” battles – even after many fighters have been died from their injuries. Donga stick fights take place after the harvests, the Surmas count days owing to knots on a long stem of grass or jags on the trunk of a tree dedicated to that specific use. Here: A tribeswoman sporting a huge lip plate and wearing a skinned animal carcass on her head. (Photo by Eric Lafforgue/Exclusivepix Media)

People look at a RoboThespian humanoid robot at the Tami Intelligence Technology stall at the WRC 2016 World Robot Conference in Beijing, China, October 21, 2016. The conference showcased China's burgeoning robot industry as the nation seeks to increase the use of robots in its manufacturing and service industries. (Photo by Thomas Peter/Reuters)

A decorated human skull or “natitas”, sits on a blanket inside the Cementerio General chapel, during the Natitas Festival celebrations, in La Paz, Bolivia, Tuesday, November 8, 2016. The “natitas” are cared for and decorated by faithful who use them as amulets believing they serve as protection, the tradition marks the end of the Catholic All Saints holiday, but is not recognized by the Catholic church. (Photo by Juan Karita/AP Photo)