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 16-meter-high snowman is nearly completed by the Songhua River in Harbin City, northeast China's Heilongjiang Province on December 7, 2022. (Photo by Rex Features/Shutterstock)

Relatives mourn over the shrouded body of Mohammad Abed, who is killed in an Israeli airstrike on a shelter in Gaza City, during his funeral in Gaza City, on April 19, 2025. (Photo by Majdi Fathi/NurPhoto/Rex Features/Shutterstock)

Honor guards are viewed during an official welcoming ceremony for Turkish President Recep Tayyip Erdogan by Albanian President Bajram Begaj, in Tirana, Albania on October 10, 2024. Turkish President Recep Tayyip Erdogan was welcomed by Albanian President Bajram Begaj with an official ceremony ahead of their meeting. (Photo by Mehmet Ali Ozcan/Anadolu via Getty Images)

Farmer Tom Spilman harvests some of the 125,000 pumpkins at Spilman's Pumpkin Farm in Sessay, near Thirsk, North Yorkshire, UK on Monday, September 25, 2023, ahead of the opening of Pumpkin Fest 2023 on Saturday. (Photo by Danny Lawson/PA Images via Getty Images)

A model presents a creation made with chocolate by designer Wang Jingzhi and Maitre Chocolatier Roberto Rinaldini during the international exhibition of chocolate “Salon du Chocolat” in Milan, Italy, February 12, 2016. (Photo by Stefano Rellandini/Reuters)

A shepherd and his flock in the Bitlis province of eastern Turkey in the first decade of April 2024. Shepherds regularly embark on gruelling journeys through the dusty outback, as they take their sheep to the high plateaus needed for grazing and then back to villages for milking. (Photo by Kahraman Kaya/Solent News)

In the spring of 1965, within weeks of 3,500 American Marines arriving in Vietnam, a 39-year-old Briton named Larry Burrows began work on a feature for LIFE magazine, chronicling the day-to-day experience of U.S. troops on the ground – and in the air – in the midst of the rapidly widening war. The photographs in this gallery focus on a calamitous March 31, 1965, helicopter mission; Burrows’ “report from Da Nang”, featuring his pictures and his personal account of the harrowing operation, was published two weeks later as a now-famous cover story in the April 16, 1965, issue of LIFE.

Photo: Man your battle stations: The crew chief of helicopter Yankee Papa 13, lance corporal James C. Farley, mans an M-60 machine gun during a mission near Da Nang, Vietnam on March 31, 1965. (Photo by Larry Burrows/Time & Life Pictures)