A street in the Cuban capital, Havana, is home to 12 sets of twins, ranging from toddlers to senior citizens. Some say it could be something in the water. Others point to a tree with mystical significance for locals. And maybe it's just chance. Photo: In this September 29, 2013 photo, nine-year-old twin sisters Camila, left, and Carla Rodriguez pose for a portrait along their street in Havana, Cuba. 12 sets of twins live along two consecutive blocks in western Havana, ranging in age from newborns to senior citizens. “We love living on this block because we have twin friends”, said Carla. (Photo by Ramon Espinosa/AP Photo)

Self-employed pedicab driver Danilo Guerra, 25, uses his mobile phone as he waits for clients in downtown Havana April 12, 2016. (Photo by Alexandre Meneghini/Reuters)

Ivan Shamyanok, 90, shaves in his house in the village of Tulgovichi, near the exclusion zone around the Chernobyl nuclear reactor, Belarus March 15, 2016. “My sister lived here with her husband. They decided to leave and soon enough they were in the ground ... They died from anxiety. I'm not anxious. I sing a little, take a turn in the yard, take things slowly like this and I live”, he said. (Photo by Vasily Fedosenko/Reuters)

A sledding dog is covered in ice after spending the night in the open air with his musher at the polar base of Val-Cenis, as they ready for the next stage of the 12th edition of “La Grande Odyssee” sledding race across the Alps on January 17, 2016 in Val Cenis Lanslevillard. (Photo by Jean-Philippe Ksiazek/AFP Photo)

Egmont National Park in New Zealand with Mt. Taranaki at its center is seen in a Landsat 8 satellite image taken July 3, 2014 and released by NASA November 14, 2014. The image is from the book “Sanctuary: Exploring the World's Protected Areas from Space”, published by the Institute for Global Environmental Strategies with support from NASA, which was released this week. (Photo by Reuters/NASA/USGS)

North Korean traffic police women chat next to a residential building while off duty Tuesday, October 18, 2016, in Pyongyang, North Korea. (Photo by Wong Maye-E/AP Photo)

Life-size sеx dolls are displayed during the 2016 AVN Adult Entertainment Expo at the Hard Rock Hotel & Casino on January 20, 2016 in Las Vegas, United States. (Photo by Gabe Ginsberg/FilmMagic)

A child plays with a soap bubble on the city hall plaza on March 14, 2015 in Paris. (Photo by Dominique Faget/AFP Photo)