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.

Ryo Minemizu, one of Japan’s emerging stars in the field of marine life photography and the 2017 winner of the Nikkei National Geographic photography prize, captures the beauty and complexity of plankton that drift in our planet’s oceans and other bodies of water in meticulous detail. Here: Batesian mimicry by a Soleichthys fish larva. (Photo by Ryo Minemizu/The Guardian)

Women quench their thirst with the tap water on a hot summer afternoon during heatwave in Prayagraj on June 10, 2024. India's heatwave is the longest ever to hit the country, the government's top weather expert said on June 10 as he warned people will face increasingly oppressive temperatures. Parts of northern India have been gripped by a heatwave since mid-May, with temperatures soaring over 45 degrees Celsius (113 degrees Fahrenheit). (Photo by Anil Shakya/AFP Photo)

Standalone picture dated June 7th, 2022 shows Flt Lt Adam O’Hare rehearsing in the iconic Typhoon plane over Lincolnshire yesterday (Tues) as he trains for this summers airshows with vapour trails over the wing. The phenomenon is caused by low pressure areas created on the aircraft's skin and wings as it moves through moist air. As the pressure drops so does the temperature, and if the temperature reaches the saturation point, water vapor is created. (Photo by Claire Hartley/Bav Media)

Lebanese women smoke nargileh (water pipe) and watch a streaming broadcast of the FIFA World Cup 2022 group G soccer match between Brazil and Switzerland, at a café-restaurant in the area of Sabtiyeh, north of Beirut, on November 28, 2022. Lebanon being hit hard by the economic crisis, the country did not obtain the rights to broadcast the 2022 World Cup this year, depriving Lebanese fans of the World Cup. (Photo by Joseph Eid/AFP Photo)

Thai residents carrying a basin with a dog inside wade through water at a flooded street during a downpour in central Yala, southern province, Thailand, 28 November 2024. Seven provinces in southern Thailand are facing severe flooding after heavy rains caused by a strong northeast monsoon, affecting thousands of people and forcing the closure of schools and roads, according to the Department of Disaster Prevention and Mitigation. (Photo by Nakharin Chinnawornkomol/EPA/EFE)

“Echus Chasma is a chasma in the Lunae Planum high plateau north of the Valles Marineris canyon system of Mars. Clay has been found in Echus Chasma that means that water once sat there for a time. Echus Chasma is approximately 100 km long and 10 km wide, with valleys ranging in depth from around 1 km to 4 km”. – Wikipedia

Photo: In this handout image supplied by the European Space Agency (ESA) on July 16, 2008, The Echus Chasma, one of the largest water source regions on Mars, is pictured from ESA's Mars Express. The data was acquired on September 25, 2005. The dark material shows a network of light-coloured, incised valleys that look similar to drainage networks known on Earth. It is still debated whether the valleys originate from precipitation, groundwater springs or liquid or magma flows on the surface. (Photo by ESA via Getty Images)