A worker pauses for a sandwich, resting on a girder during the construction of a skycraper. (Photo by Hulton Archive/Getty Images). Circa 1930

Two guards perform an execution in China, one holding the gun, the other holding a mask over the victim's face. (Photo by General Photographic Agency/Getty Images). Circa 1925

A vervet monkey passes in front of a woman on the shores of lake Naivasha, Kenya January 24, 2017. (Photo by Goran Tomasevic/Reuters)

An artist's impression of a growing supermassive black hole located in the early Universe is seen in this NASA handout illustration released on June 15, 2011. Using the deepest X-ray image ever taken, astronomers found the first direct evidence that massive black holes were common in the early universe. This discovery from NASA's Chandra X-Ray Observatory shows that very young black holes grew more aggressively than previously thought, in tandem with the growth of their host galaxies. (Photo by Reuters/NASA/Chandra X-Ray Observatory/A.Hobart)

The Blue Man Group performs on stage during a media preview ahead of their show in Singapore on March 31, 2016. Blue Man Group was started by three friends in New York in 1991 as a way to celebrate the human spirit through music, science, art and theater. (Photo by Roslan Rahman/AFP Photo)

An young Indian Jain devotee dressed as Lord Krishna participates in a religious rally organised on the occasion of Mahavir Jayanti in Kolkata on April 2, 2015. The most important religious holiday in Jainism, Mahavir Jayanti celebrates the birth of Mahavira, the last Tirthankara, which is generally accepted as 599 BCE. (Photo by Dibyangshu Sarkar/AFP Photo)

A girl plays on a pile of discarded flowers outside a market, the day after the Diwali celebrations in Mumbai, India October 31, 2016. (Photo by Shailesh Andrade/Reuters)

“The Sunsetter”. An EF-4 tornado rips through the open space of farmland near Rozel, Kansas. This tornado moves slowly but powerful towards the setting sun an gets its beautiful color right before sunset. Storm Chasers are spotting on the left side. Photo location: Rozel, Kansas. (Photo and caption by Dennis Oswald/National Geographic Photo Contest)

ATTENTION! All pictures are presented in high resolution. To see Hi-Res images – just TWICE click on any picture. In other words, click small picture – opens the BIG picture. Click BIG picture – opens VERY BIG picture.