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.

“The Boeing X-45 unmanned combat air vehicle is a concept demonstrator for a next generation of completely autonomous military aircraft, developed by Boeing's Phantom Works. Manufactured by Boeing Integrated Defense Systems, the X-45 was a part of DARPA's J-UCAS project”. – Wikipedia

Photo: Two X-45A Unmanned Combat Air Vehicles (UCAV) are shown to members of the news media July 11, 2002 at Edwards Air Force Base, California. The X-45A, developed by The Defense Advanced Research Projects Agency and the Boeing Company, is the first unmanned system designed from inception for combat missions. (Photo by David McNew/Getty Images)

Thousands of revelers continue to enjoy themselves throughout the night on Sunrise Beach on February 25, 2005 in Haadrian, Koh Phangan. (Photo by Shaul Schwarz/Getty Images)

Meenakshi Amman Temple and Meenakshi Amman Kovil is a historic Hindu temple located on the southern bank of the Vaigai River in the temple city of Madurai, Tamil Nadu, India. It is dedicated to Parvati, known as Meenakshi, and her consort, Shiva, here named Sundareswarar.

A brilliant sunset makes for a fun silhouette picture by jumping between sand bars at Shi Shi Beach on the Olympic Peninsula Friday July 17, 2015. (Photo by Bettina Hansen/The Seattle Times)

A child prays in front of the cenotaph dedicated to the victims of the atomic bombing at the Hiroshima Peace Memorial Park in Hiroshima, western Japan Friday, August 6, 2021. Hiroshima on Friday marked the 76th anniversary of the world's first atomic bombing of the city. (Photo by Kyodo News via AP Photo)

Kamaz' Russia driver Andrey Karginov, co-driver Andrey Mokeev and Igor Lenonov compete during the Stage 6 of the Dakar 2020 between Ha'il and Riyadh, Saudi Arabia, on January 10, 2020. (Photo by Franck Fife/AFP Photo)