A bunker at aformer Swiss artillery fortress called Heldsberg stands near the town of St. Margareten, Switzerland March 22, 2015. Heldsberg fortress, located on the Swiss-Austrian border near the River Rhine and Lake Constance was built from 1938 to 1940 and remained in military use until 1992. Since 1993 it is open to the public as Fortress Museum Heldsberg. (Photo by Arnd Wiegmann/Reuters)

The new wax figure of American singer Jennifer Lopez is unveiled on May 21, 2003 at Madame Tussauds, London. The waxwork is the first ever blushing figure. (Photo by Bruno Vincent/Getty Images)

A glass skywalk in Wanyuan, Sichuan province, built along the side of a cliff, is the highest such skywalk anywhere in China on January 31, 2017. Some visitors have been proven to be terrified by the experience had to brace against the wall in fear. (Photo by Chinanew.com/AsiaWire)

Indian Naga Sadhus, or naked holy men, participate in a procession before taking a “shahi snans”, or holy bath, at the Sangam river, the confluence of three of the holiest rivers in Hindu mythology, the Ganga, the Yamuna and the Saraswati, during Kumbh Mela festival in Allahabad, Uttar Pradesh, India, 15 January 2019. The Hindu festival is one of the biggest in India and will be held from 15 January to 04 March 2019 in Allahabad. (Photo by Rajat Gupta/EPA/EFE)

Mikhail Kalashnikov, the father of the world's most popular assault rifle, is handed an AK-74 November 23, 2002 in Izhevsk,1000 East km. from Moscow. November 23 marked the 55th anniversary of the release of the first Kalashnikov gun. According to the Moscow-based Center for Analysis of Strategic and Technologies some 70 million to 100 million Kalashnikovs have been built worldwide since 1947, compared about 7 million to Kalashnikov's Western rival the M-16 assault rifles. (Photo by Oleg Nikishin/Getty Images)

Gorillas at Royal Burgers’ Zoo, Arnhem, Netherlands, on November 28, 2013. (Photo by Vidi Photo/Startraks Photo New York)

Sergeant Andrew Garrett watches K-Dog, a bottlenose dolphin attached to Commander Task Unit 55.4.3, leap out of the water while training near the USS Gunston Hall March 18, 2003 in the Persian Gulf. (Photo by U.S. Navy/Getty Images)