A traveller washes his horse in the River Eden in preparation for selling at the Appleby Horse Fair on June 3, 2011 in Appleby, England. Appleby Horse Fair has existed under the protection of a charter granted by James II since 1685. It is one of the key gathering points for the Romany, gypsy and traveling community. Appleby Horse Fair is attended by about 5,000 travelers who come to buy and sell horses. The animals are washed and groomed before being ridden at high speed along the “mad mile” for the viewing of potential buyers. (Photo by Christopher Furlong/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)

South Korean police officers show their martial arts' skills during the official launch ceremony of the 2012 Seoul Nuclear Security Summit on February 15, 2012 in Seoul, South Korea. The Korean National Police Agency launched a security squad, exclusively established for the successful hosting of the 2012 Seoul Nuclear Security Summit. The 2012 Seoul Nuclear Security Summit will be held in Seoul from March 26-27, 2012. (Photo by Chung Sung-Jun/Getty Images)

Tourists walk amongst beach foam in the wake of cyclonic conditions at Currumbin Beach on December 15, 2020, after wild weather lashed Australia's Northern New South Wales and South East Queensland with heavy rain, strong winds and king tides. (Photo by Patrick Hamilton/AFP Photo)

This photo provided by the North Korean government shows North Korean leader Kim Jong Un, center, is surrounded by performers during a celebration marking the nation's 74th anniversary in Pyongyang, North Korea, on September 8, 2022. (Photo by Korean Central News Agency/Korea News Service via AP Photo)

A man walks with a Cyberdog, produced by Chinese tech company Xiaomi, on February 19, 2022 in Beijing, China.The quadruped robots, often owned by tech and robotic enthusiasts, do not have a specific purpose so far, but the open source nature of the robots could make them suitable for several applications in the future. (Photo by Andrea Verdelli/Getty Images)

Wang Zhengqing, a 74 year old pneumoconiosis patient, smokes his pipe at Yangjia Hospital in Wuyi County, Zhejiang Province, China October 19, 2015. Former miner Wang was diagnosed with the disease, which is caused by dust inhalation, when he was 24 and has lived at Yangjia Hospital for ten years. (Photo by Damir Sagolj/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.