A supporter of the team of Ukraine cheers prior to the Euro 2016 Group C soccer match between Ukraine and Poland at the Velodrome stadium in Marseille, France, Tuesday, June 21, 2016. (Photo by Thanassis Stavrakis/AP Photo)

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.

A Brazil fan waits for the start of the group A World Cup soccer match between Brazil and Croatia, the opening game of the tournament, in the Itaquerao Stadium in Sao Paulo, Brazil, Thursday, June 12, 2014. (Photo by Felipe Dana/AP Photo)

In this photo posted on Twitter, Sunday, May 3, 2015, and provided by NASA, Italian astronaut Samantha Cristoforetti sips espresso from a cup designed for use in zero-gravity, on the International Space Station. Cristoforetti, the first Italian woman in space, fired up the first espresso machine in space, which uses small capsules, or pods, of espresso coffee. (Photo by AP Photo/NASA)

In this photo provided by Jean Revillard, Solar Impulse 2, a plane powered by the sun's rays and piloted by Andre Borschberg, approaches Kalaeloa Airport near Honolulu, Friday, July 3, 2015. His 120-hour voyage from Nagoya, Japan broke the record for the world's longest nonstop solo flight, his team said. (Photo by Jean Revillard/Global Newsroom via AP Photo)

A Southwest Airlines jet takes off from Reagan National Airport with a thunderhead to the east on June 20, 2017 in Alexandria, VA. (Photo by Jonathan Newton/The Washington Post)

Dancer Beth Bracegirdle of the Balbir Singh Dance Company practises at the Billingham Forum pool in Billingham, UK on July 20, 2016, ahead of the 52nd Billingham international folklore festival of world dance in August. (Photo by Owen Humphreys/PA Wire)

A woman walks in front of an art installation made of artificial fruits and vegetables during the “Moscow Autumn” festival in central Moscow, September 14, 2015. (Photo by Maxim Zmeyev/Reuters)