A Galapagos Tortoise shell is used as a foot rest at Heathrow Airport's Animal Reception Centre on January 25, 2011 in London, England. Many animals pass through the centre's doors ranging from exotic animals such as snow leopards and elephants, snakes and crocodiles, to the more common such as cats and dogs. In 2010 alone the centre processed approximately 10,500 cats and dogs, 1,300 birds, 105,000 day old chicks, 246,000 reptiles, 230 horses and 29 million fish. Most animals are part of zoo transfer schemes, the pet trade, or are pets in transit. (Photo by Dan Kitwood/Getty Images)

A concept illustration of the world's first forest in the sky, the Bosco Verticale green twin towers currently under construction in Milan, Italy. Towering over the city skyline the world's first forest in the sky will be a sight to behold. With tree equal to one hectare of forest spanning 27 floors these 365 and 260 foot emerald twin towers will be home to an astonishing 730 trees, 5,000 shrubs and 11,000 ground cover plants. (Photo by Boeri Studio)

First lady Michelle Obama (R), joined by daughters Sasha Obama (C) and Malia Obama, is presented with the official White House Christmas Tree on November 25, 2011 in Washington, DC. The tree, a 19-foot-tall balsam fir, was grown on Schroeder's Forevergreens farm near Neshkoro, Wisconsin. (Photo by Brendan Hoffman/Getty Images)

Few people haven’t heard about the ancient city of Persepolis, which lies at the foot of the Mountain of Mercy (Kuh-I-Rahmat). In ancient times, Persepolis was the capital of the Achaemenid Empire. Regretfully, it was burned by the Greeks in 330 BC after they looted the immense treasure of this city. It is said that Greeks needed 5,000 camels and 20,000 mules to carry all the treasures from Persepolis. The only thing of Persepolis that has survived the wear of time is the ginormous stone terrace 530 by 330 meters adorned by elaborate stone sculptures. It is amazing how intricately detailed some of the sculptures are, despite the fact that they were created many centuries ago.

The Tibetan night sky was captured in these beautiful images showing the stunning buildings and statues in the Himalayan mountains. Grey Chow, 33, traveled for two hours to get to the Spiti Valley to capture the starry backdrop along the isolated, deserted roads. The senior project engineer was able to take amazingly clear images thanks to the limited amount of pollution at the 4,500-foot (1371m) altitude. (Photo by Grey Chow/Caters News Agency)

Six month- old baby elephant “Clear Sky” is kept afloat with the help of a harness during a hydrotherapy session at a local veterinary clinic in Chonburi Province on January 5, 2017. After losing part of her left foot in a snare in Thailand, baby elephant 'Clear Sky' is now learning to walk again – in water. (Photo by Roberto Schmidt/AFP Photo)

A female soccer player controls a ball during a training session at the Golab Trust Sport Complex in Kabul March 10, 2014. Despite decades of conflict in Afghanistan, and several recent militant attacks, the country's capital Kabul is home to a vibrant youth scene of musicians, artists, athletes and activists. Shopping malls and cafes stand in the city, which is nonetheless beset by infrastructure problems and instability. (Photo by Morteza Nikoubazl/Reuters)