A thirty-year-old Dutch demonstrator displays a sign that reads: “Glad to be Gay” during a gay people march in Frankfurt, Germany on Saturday, July 28, 1979 which ended a week long homosexual meeting. Hundreds of homosexual converged for a week of movies, theater, rock concerts and workshops on gay rights. (Photo by Rolf Boehm/AP Photo)

A bunker at aformer Swiss artillery fortress called Heldsberg stands near the town of St. Margareten, Switzerland March 22, 2015. Heldsberg fortress, located on the Swiss-Austrian border near the River Rhine and Lake Constance was built from 1938 to 1940 and remained in military use until 1992. Since 1993 it is open to the public as Fortress Museum Heldsberg. (Photo by Arnd Wiegmann/Reuters)

“Richard Wilson (born May 24, 1953) is a sculptor, installation artist and musician. Wilson's work is characterised by architectural concerns with volume, illusionary spaces and auditory perception”. – Wikipedia

Photo: An installation by the artist Richard Wilson, entitled “Turning the Place Over”, is built into the condemned Cross Keys House in Moorfields as part of the Capital of Culture for 2008, on June 25, 2007 in Liverpool, England. The piece consists of an 8 metre ovoid cut from the building's facade that oscillates in three dimensions. (Photo by Jim Dyson/Getty Images)

An Indian soldier from the international peace keeping force (IPKF) instructs young Sri Lankan recruits in shooting, part of the training given to the citizen's volunteer force in the North-Eastern Sri Lankan city of Batticaloa, September 28, 1989. (Photo by Barbara Walton/AP Photo)

The Photographers 2015 runs from 25 November to 23 December at Osborne Samuel and Beetles+Huxley, London. Here: Untitled, 1950, by Bert Hardy. (Photo by Bert Hardy/Beetles+Huxley & Osborne Samuel)

Tourists play on the “Big” piano inside of the toy store FAO Schwarz on the last day that the store will be open in New York, July 15, 2015. FAO Schwarz will officially close the doors of its flagship Fifth Avenue toy store in New York City on Wednesday night, to the dismay of shoppers charmed by the iconic destination for childhood fun. (Photo by Lucas Jackson/Reuters)

A little girl takes a picture of a lion in the zoo in Frankfurt, Germany, Tuesday, September 13, 2016. (Photo by Michael Probst/AP Photo)

China Airlines stewardess Wang Wen Hwang leaps from the burning China Airlines plane after assisting the passengers to safety February 27, 1980. Miss Wang saved most of the lives of the passengers despite her injuries. She was the last to leave the planes. (Photo by AP Photo)