Two Herens cows lock horns during the qualification round of the annual “Battle of the Queens” cow fight finals in Aproz, in the western Alpine canton of Valais May 5, 2013. Each year when taken to the alpine pastures, the cows test their strength and fight for the herd's leadership. The competition continues until a new queen has forced all the other cows to retreat. (Photo by Valentin Flauraud/Reuters)

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)

Alexo Carmona, 2, looks at Coco, a two-year-old pony, in downtown Havana, in this March 6, 2015 file photo. Nearly a quarter of a million people follow the Reuters Instagram account – and it's still growing fast. To mark the mid-point of 2015, Reuters has compiled the twenty most-liked pictures so far. This picture was 20th most popular. (Photo by Alexandre Meneghini/Reuters)

Damaged train coaches at the site of a train accident, 180 kilometers from Bhopal near Harda district of Mahdya Pradesh, India, 05 August 2015. At least 25 people died when two passenger trains derailed in central India after heavy monsoon rains flooded railway tracks, officials said. Ten coaches from the trains toppled while approaching a small bridge just before midnight. (Photo by Sanjeev Gupta/EPA)

Disguised participants strike poses on a car during the ancient carnival of Ituren, in the northern Spanish Navarra province on January 30, 2017. The yearly three day festivities, revolving mainly around agriculture and principally sheep hearding, run on the last Sunday, Monday and Tuesday of January where Navarra Valley locals from two villages dress up and participate in a variety of activites as they perform a pilgrimage through each village. (Photo by Ander Gillenea/AFP Photo)

An injured Iraqi Emergency Response Division (ERD) soldier hit by a mortar is held by another officer as they wait for medics to arrive at the Islamic State occupied Mosul Airport in west Mosul, part of the offensive to retake the city some two years after it fell to the hardline jihadist group, February 23, 2017. Iraqi forces encountered stiff resistance with improvised explosives, heavy mortar fire and snipers hampering their advance before they successfully took the airport. (Photo by Martyn Aim/Getty Images)

An Egyptian worker prepares to lift parts of a statue at the site of a new archeological discovery at Souq Al-Khamis district in Al-Matareya area, Cairo, Egypt on March 9 2017. According to the Ministry of Antiquities, two 19th dynasty royal statues were found in parts in the vicinity of King Ramses II temple in ancient Heliopolis (Oun) Sun Temples by a German-Egyptian archeological mission. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

This picture taken on March 16, 2017 shows a crew member introducing the dining car of the Train Suite Shiki- Shima, operated by East Japan Railway, in Tokyo during a press preview. The luxury sleeper Shiki- Shima, which can accommodate up to 34 passengers, has 10 cars, including a lounge car, a dining car and two observatory cars. The train has only 17 cabins, all suites, and the most expensive room, known as Shiki- Shima Suite, is priced at 950,000 yen (8480 USD) per person when shared by two people. (Photo by AFP Photo/JIJI Press)