“Just hanging out”. As full autumn hits the valley of Hallingdal in Norway, this bear chills out in a tree which seems to barely cover its weight. Photo location: Flå, Hallingdal, Norway. (Photo and caption by Jorgen Tharaldsen/National Geographic Photo Contest)

Here Goes River captures Japanese photographer Aya Fujioka’s home town of Hiroshima in 2017. The award-winning series documents the quiet, everyday spaces of the city – mundane, almost incidental scenes that are suffused with the invisible weight of the past. (Photo by Aya Fujioka)

A tunnel with electric switches are seen in Josip Broz Tito's underground secret bunker (ARK) in Konjic, October 16, 2014. In the early 1950s, Josip Broz Tito, the late leader of the former Yugoslavia, ordered the building of the secret bunker, located 900 feet (270 m) underground and near the Bosnian town of Konjic, to safeguard the country's ruling class in case of a nuclear attack. Construction at the complex, which had a cost equivalent price tag of $4.6 billion, continued until 1979, the year before Tito died. (Photo by Dado Ruvic/Reuters)

Wladimir Klitschko (L) and David Haye attend a press conference on June 27, 2011 in Hamburg, Germany to preview the heavy weight title fight between them which will be held on the 2nd July 2011 at the Imtech Arena. (Photo by Scott Heavey/Getty Images)

“A robot suit that can help the elderly or disabled get around was given its global safety certificate in Japan on February 27, 2013, paving the way for its worldwide roll-out”. Photo: Robot suit “Hybrid Assistive Limb (HAL)” worn by a man developed by University of Tsukuba is seen lifting a 30kg weight during 2005 International Robot Exhibition on November 30, 2005 in Tokyo, Japan. By wearing the power suit, it makes it easier to move and lift heavy things. (Photo by Koichi Kamoshida)

Farmer Zhang Xianping rides his pig "Big Precious" during an interview with the media, in Zhangjiakou, Hebei province, China, November 2, 2015. Zhang, a pig breeder, instead of killing it, decided to keep the two-year-old "Big Precious" as pet when its weight reached 600 kg, according to local media. (Photo by Reuters/China Daily)

Bulls fight during the annual Bullfighting Festival on March 17, 2010 in Cheongdo, South Korea. More than 130 bulls from South Korea and abroad charge and lock horns in the annual festival which was run March 21, 2010. The bulls are grouped into three weight categories and fight head on until one of the bulls turns its head and runs away. (Photo by Chung Sung-Jun/Getty Images)

Children watch a rabbit, jumping over a hurdle at an obstacle course the 5th Open Rabbit Sport Tournament (5. offene Kaninchensport Turnier) on August 28, 2011 in Rommerz near Fulda, Germany. Eighty rabbits competed in light-weight, middle-weight and jumping-for-points categories at today's tournament in Rommerz that is based on Kanin Hop, or Rabbit Hopping. Rabbit Hopping is a growing trend among pet rabbit owners in Central Europe and the first European Championships are scheduled to be held later this year in Switzerland. (Photo by Ralph Orlowski/Getty Images)