These adrenaline-junkie climbers go to extraordinary lengths, and heights, to take a selfie. Hundreds of metres above the ground, the climbers risk their life and liberty as they scale huge structures and photograph the results. Known as urban exploration, the aim is to find extremely high and almost inaccessible city buildings and reach their dizzying summits. (Photo by Yaroslav Segeda/Solent News)

U.S. Army helicopters providing support for U.S. ground troops fly into a staging area fifty miles northeast of Saigon, Vietnam, August 28, 1966. Helicopter fuel is stored in the large rubber tanks, foreground. (Photo by Henri Huet/AP Photo)

A Russian Soyuz MS space capsule stands on the ground shortly after its landing with International Space Station (ISS) crew members Kate Rubins of the U.S., Anatoly Ivanishin of Russia and Takuya Onishi of Japan, as a rescue helicopter lands nearby, outside the town of Dzhezkazgan (Zhezkazgan), Kazakhstan, October 30, 2016. (Photo by Dmitri Lovetsky/Reuters)

Workers attempt to bring a tranquillised black rhino to the ground before dehorning in an effort to deter the poaching of one of the world's endangered species, at a farm outside Klerksdorp, in the north west province, South Africa, February 24, 2016. (Photo by Siphiwe Sibeko/Reuters)

An actor portraying Jesus Christ takes part in the interactive street-theatre Passion play “Il-Mixja” (The Way), one of a series of Holy Week activities in the run-up to Easter, in the grounds of Mount Carmel Mental Hospital in Attard, outside Valletta, Malta, March 22, 2016. (Photo by Darrin Zammit Lupi/Reuters)

Labrador puppies “Hoey” (L) and “Hatton”, named in honor of September 11, 2001 attack victims Patrick Hoey and Lenny Hatton who died in the World Trade Center, are pictured on the grounds of the Pentagon near Washington, June 28, 2011. (Photo by Jason Reed/Reuters)

Anna Malova, Miss Russia 1998, poses on a pool table at The Campbell Apartment restaurant in Grand Central Station on November 18, 1999. She makes her motion picture debut in the movie “Above Ground”. (Photo by Richard Corkery/NY Daily News Archive via Getty Images)

Convicted murderer Hector Alvarado Mazariegos, right, drops to the ground as he is hit by bullets of a Guatemala firing squad in the public cemetery at Mazatenango, June 28, 1975. His companion, Rocael Ortiz, met the same fate a few seconds later. Both were convicted of murder. (Photo by AP Photo/Anzueto)