Team Strong Silvers member Ngai Hin Kwok, 66, works out as teammate Ng Siu Chi, 57, watches at a stadium in Singapore March 15, 2015. Team Strong Silvers, is a group of senior citizens who train in calisthenics. The trio trains individually at least three times a week, and meets up for joint calisthenics at least twice a month. (Photo by Edgar Su/Reuters)

Durga Kami, 68, who is studying tenth grade at Shree Kala Bhairab Higher Secondary School, walks with his classmate Sagar Thapa, 14, as they head to school in Syangja, Nepal, June 5, 2016. (Photo by Navesh Chitrakar/Reuters)

In the works of a photographer named Dave – who goes by Freaktography and never gives out his full name – haunting abandonment leaps from images of discarded machinery, tools and factory essentials. (Photo by Freaktography/Caters News Agency)

“Winter shapes, Moscow river”. Moscow river at this part is never covered by ice. When the temperature is very low it's possible to see a strong fog. Morning light and pipes of the oli factory creates a fantastic landscape. Photo location: Moscow, Russia. (Photo and caption by Sergey Rumyantsev/National Geographic Photo Contest)

Admiral Flota Sovetskovo Soyuza Kuznetsov (Russian: Адмирал флота Советского Союза Кузнецов “Fleet Admiral of the Soviet Union Kuznetsov”), originally named Riga, renamed Leonid Brezhnev then Tbilisi) is an aircraft cruiser (heavy aircraft carrying missile cruiser (TAVKR) in Russian classification) serving as the flagship of the Russian Navy. She was originally commissioned in the Soviet Navy, and was intended to be the lead ship of her class, but the only other ship of her class, Varyag, was never commissioned and was sold to the People's Republic of China by Ukraine under the condition she would never be refitted for combat. Kuznetsov was named after the Admiral of the Fleet of the Soviet Union Nikolai Gerasimovich Kuznetsov.

A talented body painter has created a series of mind-bending illusions that cover entire torsos. Natalie Fletcher’s work are enough to make people double-take, the spiraling patterns of some appearing to fade into the abyss. In other works, the artists designs look as though they are never ending, while some show body parts appearing to protrude from models chests. The idea behind the ongoing series came to Natalie, 30, as a means of keeping entertained during the winter months. Here: Optical illusion bodypaint. (Photo by Natalie Fletcher/Cater News)