Armed Yemeni children sit in the back of a pick up truck with fighters loyal to Yemen's Saudi-backed President Abedrabbo Mansour Hadi in the Dar saad neighbourhood of the southern Yemeni city of Aden on May 10, 2015, as they continue to battle Shiite Huthi rebels. (Photo by Saleh Al-Obeidi/AFP Photo)

People are seen in the crowd as Serbian Emir Kusturica & The No Smoking Orchestra performs during the third day of the Mexican musicial festival Vive Latino, at the Foro Sol in Mexico City, on March 29, 2014. (Photo by Alfredo Estrella/AFP Photo)

Jiff with Playboy Playmates arrives at the Playboy Super Bowl XLIX Party on Friday, January 30, 2015 in Scottsdale, Ariz. (Photo by Omar Vega/Invision/AP Photo)

Gigi Hadid and Emily Ratajkowski celebrated the opening of the shopping centre by taking part in the evening's ribbon cutting ceremony in Mykonos, Greece on June 30, 2018. (Photo by Richard Young/Rex Features/Shutterstock)

A wild leopard runs on the stairs as it tries to escape from a compound of a house in Kathmandu, Nepal June 1, 2016. (Photo by Navesh Chitrakar/Reuters)

Lake Baikal is the world's oldest lake, at 25 million years (possibly older), and deepest, averaging 744.4 metres (2,442 ft).

Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the world, containing roughly 20% of the world's unfrozen surface fresh water.

Legend by Damien Hirst in the gardens of Chatsworth House on September 9, 2011 in Chatsworth, England. The never before seen work by Hirst is part of the Beyond Limits exhibition of modern and contemporary sculpture displayed in the gardens of Chatsworth by Sotherby's between 9th September to 30th October 2011. (Photo by Christopher Furlong/Getty Images)

Goats wait to get unloaded from a vehicle at a livestock market during Dashain, the biggest religious festival for Hindus in Nepal, in Kathmandu, Nepal October 4, 2016. (Photo by Navesh Chitrakar/Reuters)