A reveler waves a gay pride flag in front of the historic gay bar The Stonewall after the passing of a bill legalizing gay marriage in New York State on June 24, 2011 in New York City. New York State now joins Connecticut, Massachusetts, New Hampshire, Vermont, Iowa and Washington, D.C. in legally recognizing gay marriage. (Photo by Spencer Platt/Getty Images)

Built for over a million people, the city of Ordos was designed to be the crowning glory of Inner Mongolia. Doomed to incompletion however, this futuristic metropolis now rises empty out of the deserts of northern China. Only 2% of its buildings were ever filled; the rest has largely been left to decay, abandoned mid-construction, earning Ordos the title of China's Ghost City.

Hot air balloons take to the skies over Bristol city centre on August 6, 2012 in Bristol, England. The early morning flight of over twenty balloons over the city was organised as a curtain raiser for the four-day Bristol International Balloon Fiesta which starts on Thursday. Now in its 34th year, the Bristol International Balloon Fiesta is Europe's largest annual hot air balloon event in the city that is seen by many balloonists as the home of modern ballooning. (Photo by Matt Cardy)

This July 2014 image provided by the Bureau of Land Management shows the interior of the Natural Trap Cave in north-central Wyoming. The cave holds the remains of tens of thousands of animals, including many now-extinct species, from the late Pleistocene period tens of thousands of years ago. Scientists have resumed digging for the first time in more than 30 years. (Photo by AP Photo/Bureau of Land Management)

Erica and Hannes, from Zurich, Switzerland, were tasked with watching their friend’s 6-month-old baby overnight, and after an “extensive briefing” from the dad, they realized just how much could go wrong. The couple, both designers, decided to have some fun with their fears, making the apocalyptic scenarios come to life in a hilarious photo series now gone viral. (Photo by Erica and Hannes)

Eurocopter's X³ high-speed hybrid helicopter demonstrator performs, September 6, 2010. The Eurocopter X³ (X-Cubed) is an experimental high-speed compound helicopter developed by Eurocopter (now Airbus Helicopters). A technology demonstration platform for Eurocopter “high-speed, long-range hybrid helicopter” or H³ concept, the X³ achieved 255 knots in level flight on 7 June 2013, setting an unofficial speed record for a helicopter. (Photo by Reuters/HO/Eurocopter/Penna)

A girl swims in floodwaters in Malaysia' s northeastern town of Rantau Panjang, which borders Thailand, on January 5, 2017 Floods in two northeast Malaysian states have now forced almost 23,000 people from their homes and extra relief centres have been opened, rescue officials said on January 4. (Photo by Mohd Rasfan/AFP Photo)