A general view of Edinburgh Castle on February 7, 2012 in Edinburgh, Scotland. The castle dominates the city skyline was built on top of an extinct volcano, and has had a human settlement on the castle site since 900BC. (Photo by Jeff J. Mitchell/Getty Images)

Demonstrators throw fire bombs to riot police during violent protests in central Athens February 12, 2012. (Photo by Milos Bicanski/Getty Images)

Sean Phillips flies through the air as he demonstrates the JetLev water propelled jet pack that is strapped to his back at the Yacht & Brokerage Show on February 17, 2012 in Miami Beach, Florida. (Photo by Joe Raedle/Getty Images)

A boy sits on his father's shoulders to look at strawberries at the 7th International Strawberry Symposium on February 18, 2012 in Beijing, China. (Photo by Lintao Zhang/Getty Images)

Secret arrive during the 1st Gaon Chart K-POP Awards at Blue Square on February 22, 2012 in Seoul, South Korea. (Photo by Chung Sung-Jun/Getty Images)

Lukas Michul, a member of the “dream walker” group jumps from atop the rugged rocks overlooking the azure waters of Navagio beach, one of the Greece's most renowned leisure spots on the popular tourist island of Zakynthos on June 23, 2014. This is rope jumping – part diving, part rock climbing, with a touch of engineering. The aim of the project is to dream jump in 80 places with most ravishing nature and architecture all over the world .They plan to stage their next leaps at a cave complex in Croatia, a French viaduct, skyscrapers in Las Vegas and Johannesburg, and the Grand Canyon. (Photo by Louisa Gouliamaki/AFP Photo)

Eight-year-old Niu Dongfang trains at the No. 2 Beijing Shuangqiao School January 13, 2005 in Beijing, China. Most of students in the gymnastics school have to study more than five years from as young as age six before they become athletes. (Photo by Guang Niu/Getty Images)

Marina Bay Sands is an integrated resort fronting Marina Bay in Singapore. Developed by Las Vegas Sands, it is billed as the world's most expensive standalone casino property at S$8 billion, including cost of the prime land.