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.

An instructor (C) adjusts the posture of students of flight attendant major during a training session at Anhui Foreign Languages University, in Hefei, Anhui province, China, May 25, 2015. (Photo by Reuters/China Daily)

Carine Louis-Jean, 22, poses for a photograph in her destroyed house after Hurricane Matthew hit Jeremie, Haiti, October 17, 2016. “The roof of my house is completely gone and some of walls were destroyed. I have lost everything I had, but I thank God that I have a friend who is letting me stay at her house. I could say I'm lucky, because none of my family died during the hurricane, but I do not think I'm lucky”, said Louis-Jean. (Photo by Carlos Garcia Rawlins/Reuters)

Participants at the Dubai Run at Sheikh Zayed Road in Dubai, United Arab Emirates on November 26, 2021. (Photo by Ruel Pableo for The National)

The Heavens opened as students from Wells Blue school year 13 pupils arrived at The Bishop's Palace in Wells, Somerset on June 30, 2022 for their end of year school prom. (Photo by Jason Bryant/Apex News)

An image taken with a drone shows beach umbrellas and deck chairs as beachgoers enjoy the hot weather in Scheveningen, the Netherlands, 24 July 2019. The Royal Dutch Meteorological Institute has issued an official warning due to high temperatures affecting the country as well as Western Europe. (Photo by Sem van der Wal/EPA/EFE)

Fluffy toy panda bears as part of the art installation “Panda mie” by Italian restaurant owner Giuseppe “Pino” Fichera sit over beers at his restaurant “Pino's” to raise awareness of the COVID-19 lockdown's business impact on gastronomy in Frankfurt, Germany, November 24, 2020. (Photo by Kai Pfaffenbach/Reuters)

A drag queen waves a rainbow flag during an LGBT rights demonstration in front of the Hungarian Parliament building in Budapest, Hungary on June 14, 2021. During the protest human rights activists called on lawmakers in Hungary to reject legislation banning any content portraying or promoting homosexuality or sеx reassignment to anyone under 18. The bills, aiming at fighting pedophilia, have various amendments which would outlaw any depiction or discussion of different gender identities to youth in the public sphere. (Photo by Bela Szandelszky/AP Photo)