A tiger is painted on the backs of three models at the Three Lanes and Seven Alleys on January 3, 2012 in Fuzhou, China. (Photo by ChinaFotoPress/ChinaFotoPress)

Birds sit on the back of a zebra in the Nairobi National Park, near Nairobi, Kenya, November 21, 2018. (Photo by Baz Ratner/Reuters)

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.

An elephant enjoys its back being scrubbed by the keeper on March 1, 1950. (Photo by Fox Photos/Getty Images)

Opossums on their mothers back at a game reserve in Central Minnesota, USA, on September 2, 2013. (Photo by Caters News Agency)

Greyhounds with stuffed and sprung model monkeys strapped to their backs before a hurdle race at Wellinborough. (Photo by E. Bacon). 21st April 1928

A mouse rides on the back of a frog in floodwaters in the northern Indian city Lucknow June 30, 2006. (Photo by Pawan Kumar/Reuters)

A Pakistani labourer carries bricks on his back at a construction site at a residential area in Islamabad on March 29, 2017. (Photo by Aamir Qureshi/AFP Photo)