The Y-40 Deep Joy is the worlds deepest pool. Y-40 is projected by Architect Emanuele Boaretto and supported by the “Boaretto Group Hotel and Resort”. The name Y-40 is inspired by mathematical symbols. “Y” is the ordinate axis of the Cartesian system and “–40” means the world's record depth or our pool- that is 40 meters underground. (Photo by Courtesy Y40 Deep Joy)

Most people know Nikon as a purveyor of pro and consumer-grade digital cameras. But the company's expertise with optics bleeds over into related markets – it's one of the science community's major suppliers of microscopes. And each year the company asks the community to send it some of their favorite images of tiny objects. A panel of scientists and journalists have chosen the best of this past year's submissions, which Nikon has placed on its Small World site.

Photo: Honorable Mention. “Snow crystal, illuminated with colored lights (5x)”. (Photo by Dr. Kenneth Libbrecht, California Institute of Technology (Caltech), Department of Physics, Pasadena, California, USA)

A soldier helps another with her ear protection at the Terningmoen Camp in Elverum, Norway on March 23, 2017. Soldiers demonstrate their skills and tactics during a contract drill as they train to become part of the world's first all-female special forces unit, the Jegertroppen or “hunter troops”. (Photo by Carolina Reid/NBC News)

Sport category, winner: Yuan Peng. Liu Bingqing and Liu Yujie are twin sisters who have studied and trained in gymnastics since their early childhood in Jining, China. (Photo by Yuan Peng/Sony World Photography Awards)

Sumo wrestler Kaiho eats a “chanko” meal in Nagoya, Japan on July 18, 2017. After ending practice at 10:30 a.m., the wrestlers mingle with fans, sign autographs and pose for photos before the first of their two daily meals. (Photo by Issei Kato/Reuters)

An artist airbrushes a model during the “World Bodypainting Festival 2017” in Klagenfurt, Austria on July 28, 2017. (Photo by Leonhard Foeger/Reuters)

This undated handout photo received from the Antarctic Ocean Alliance on October 28, 2016 shows a adelie penguin jumping onto the ice in the Ross Sea in Antarctica. The world's largest marine reserve aimed at protecting the pristine wilderness of Antarctica will be created after a “momentous” agreement was finally reached on October 28, 2016 with Russia dropping its long-held opposition. (Photo by John Weller/AFP Photo/Antarctic Ocean Alliance)

Russian illustrator from South West of Siberia Artem Chebokha creates surreal digital paintings that have a peaceful yet grandiose feel to them.