Dalmatian pelicans on Lake Kerkini in Greece captured over the space of one week (16-21 January 2023) by tour guide photographer Sean Weekly. The Dalmatian pelicans resemble the winged dinosaur pterodactyl as they swoop, splash and feed in the waters of Lake Kerkini in Greece. With wings outstretched, and colourful faces and beaks on display, the birds appear to be in paradise, with the awe-inspiring Kerkini mountains as a mesmerising backdrop. (Photo by Sean Weekly/Animal News Agency)

A common gallinule runs across the water to escape a nearby alligator at Green Cay Nature Center in Boynton Beach, Florida on September 4, 2025. Unlike most waterbirds, gallinules have long toes that allow them to walk on floating vegetation. The species is known for its loud, cackling calls that often echo through wetlands. (Photo by Ronen Tivony/NurPhoto/Rex Features/Shutterstock)

A milkman crosses through floodwater at Chak Ali Sher village in Wazirabad district on August 28, 2025, after government issued a flood alert for riverside areas of Punjab province. Water has gushed into the eastern province, Pakistan's breadbasket and home to about half of its 255 million people, with three transboundary rivers swelling beyond their banks. The latest monsoon downpour has killed at least 13 people, according to the National Disaster Management Authority. (Photo by Aamir Qureshi/AFP Photo)

A young Ukrainian woman wears an ear of grain braid during a traditional Ukrainian celebration of Kupalo Night, in Warsaw, Poland, on Saturday, June 22, 2024. Ukrainians in Warsaw jumped over a bonfire and floated braids to honor the vital powers of water and fire on the Vistula River bank Saturday night, as they celebrated their solstice tradition of Ivan Kupalo Night away from war-torn home. (Photo by Czarek Sokolowski/AP Photo)

A fisherwoman repairs the fishing nets at a fishing port during the annual summer fishing ban, which covers the Bohai Sea, the Yellow Sea, the East China Sea, and the waters north of 12 degrees north latitude in the South China Sea, on June 8, 2022 in Wenling, Taizhou City, Zhejiang Province of China. (Photo by Liu Zhenqing/VCG via Getty Images)

Underwater photographer Sarah Lee uses a technique known as “duck diving” to capture these stunning photos of surfers in Hawaii. Surfers “duck dive” under the water to avoid incoming waves so they can get further out to sea. Photo: A surfer comes free from her surfboard. (Photo by Sarah Lee/Caters News)

Tourist Michel Watson found this pink dolphin making a splash in Brazil. The unusual creature, which hides deep in the Rio Negro river, was spotted leaping out of the Amazonian water brandishing its bizarre bright bubblegum color. Weighing in at nearly 300 pounds, the curious animal, known as an Amazon Pink River Dolphin, looked unusually agile as it rose above the waves. (Photo by Michel Watson)

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.