Three samurai warriors in armour, circa 1880. (Photo by Kusakabe Kimbei). P.S. All pictures are presented in high resolution.

A line of soldiers firing handguns during a training session, circa 1920. (Photo by Keystone). P.S. All pictures are presented in high resolution.

French tennis champion Suzanne Lenglen (1899–1938) high-kicking during a doubles match at the Wimbledon Lawn Tennis Championships. (Photo by Kirby/Topical Press/Getty Images). 1924

A group of boys toss their friend into the water at Good Harbor Beach in Gloucester, Massachusetts, United States on June 25, 2024. New England temperatures reached into the high 80's(F) and low 90's(F) this week after a heatwave brought temperatures close to 100(F) last week. Heat domes causing heatwaves have been hitting the US over the past week with high alerts placed in the I-95 corridor on the East Coast. The National weather service has predicted above-normal temperatures for most the US for the month of July. (Photo by Joseph Prezioso/Anadolu via Getty Images)

Revellers take part in the annual “Naval Battle” of Vallecas in Madrid, Spain July 19, 2015. The slogan for this year's water battle is “Get wet for Alfon, freedom for Alfon”, referring to Alfonso Fernandez Ortega, a Vallecas resident who was sentenced to four years in prison in June. The festival was started spontaneously in 1981 when some neighbours started to throw water at one another due to high temperatures during the Virgen del Carmen Festival. (Photo by Juan Medina/Reuters)

In this photo taken on Sunday, March 15, 2015, a Nenets woman rides steers a sled during a reindeer race at the Reindeer Herder's Day in the city of Nadym, in Yamal-Nenets Region, 2500 kilometers (about 1553 miles) northeast of Moscow, Russia. For the indigenous nomadic Nenets people, the Reindeer Herder's Day offers a chance to show their prowess in wrestling, high jumps and other traditional local sports, but, above all, reindeer races. (Photo by Dmitry Lovetsky/AP Photo)

A Dutch Military Policeman, left inside, guards part of the reconstructed cockpit, right, and forward section of the fuselage after the Dutch Safety Board presented it's final report into what caused Malaysia Airlines Flight 17 to break up high over Eastern Ukraine last year, killing all 298 people on board, during a press conference in Gilze-Rijen, central Netherlands, Tuesday, October 13, 2015. (Photo by Peter Dejong/AP Photo)

Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)