The Invasion. A quiet street in Macau. Modernization around is quickly changing the city, as documented by Paul Tsui. (Photo by Paul Tsui/National Geographic Travel Photographer of the Year Contest)

Retired builder Vasili Sidamonidze, 70, poses for a portrait at his home in Gori, Georgia, December 6, 2016. “Unfortunately, Stalin is not popular nowadays. Our people don't respect him. Only we, members of the (Communist) Party, respect him”, Sidamonidze said. “I always try to attend Stalin's birthday anniversaries in Gori. Unfortunately many people don't want to join us even if they live nearby. They look at us from their windows”. (Photo by David Mdzinarishvili/Reuters)

A worker applies colour to strings which will be used to fly kites, by a roadside in Ahmedabad, India, November 23, 2017. (Photo by Amit Dave/Reuters)

Smoke rises from a house days after part of the ground it was resting on collapsed into Lake Whitney, Texas in this June 13, 2014 file photo. I was covering the controlled burn of a house slowly falling into Lake Whitney due to the decaying cliff underneath. Asked to take photos from an aerial perspective, an instructor and I took off from Grand Prairie Municipal Airport around 9am. The burn, scheduled to start an hour later, was delayed. I love flying, but patience proved challenging as circling for nearly three hours gets boring fast. Once the fire started we only had 15 minutes to take photos because the plane was booked at 1pm. The owners invested their retirement savings in the house and were even advised by geologists that the ground was stable. To watch your investment literally go up in flames must take its toll emotionally. The owners said they don't expect their insurance to cover the loss. (Photo and caption by Brandon Wade/Reuters)

Neil Zeller's snaps were taken across Canada, where he photographs the northern lights dancing across a dark night sky. In one stunning shot, Zeller, 42, even manages to capture a flash of lightning beneath a storm cell while an aurora gives off a magnificent green glow. The photographer, from Calgary, Alberta, describes himself as a night person, and became interested in night photography about 10 years ago. (Photo by Neil Zeller/Caters News)

Street photographer Yassine Alaoui Ismaili follows 16-year-old Emeer Guesmi, aka B-boy Zulu Rema, as he trains and performs breakdance moves – all without the use of his legs. At a breakdance championship in Tunisia, Casablanca-based street photographer Yassine Alaoui Ismaili noticed an unusual competitor: Emeer Guesmi, dancing without the aid of his lower legs. He started following him as he trained and performed. (Photo by Yassine Alaoui Ismaili/The Guardian)

“Don't Leave Any Food On Your Plate”. The giraffes at Nairobi's Giraffe Manor are totally at home with humans. They will eat out of your hand, or even off your plate. Photo location: Giraffe Manor, Nairobi, Kenya. (Photo and caption by Gavin Werbeloff/National Geographic Photo Contest)

“Valentine Shmalentine”, 2011. (Photo by GillyFace)