In this Thursday, May 8, 2014 photo, guests look down from the Tilt!, a new tourist attraction that provides guests a unique view of the downtown area from the 94th floor of the John Hancock Building, after it was unveiled in Chicago. People hold onto handrails as the glass and steel facade tilts forward 30 degrees. (Photo by Ashlee Rezin/AP Photo/Sun-Times Media)

A German Air Force Officer sits astride a dead boar outside a house where he is stationed near the Western Front, in this 1918 handout picture. This picture is part of a previously unpublished set of World War One (WWI) images from a private collection. The pictures offer an unusual view of varied and contrasting aspects of the conflict, from high tech artillery to mobile pigeon lofts, and from officers partying in their headquarters to the grim reality of life and death in the trenches. The year 2014 marks the centenary of the start of the war. (Photo by Reuters/Archive of Modern Conflict London)

Jassen Todorov, 40, from San Francisco is a professor of music at San Francisco State University, but he took to helicoptering in his spare time. While he was content to keep the panoramic views he witnessed to himself, Todorov has now paired his passion for flying with photography to capture some of the United States’ undiscovered vistas. Here: Grand Prismatic Spring, Yellowstone, Wyoming. (Photo by Jassen Todorov/Caters News)

Developed for the British American Ambulance Corps, this new motorcycle ambulance is capable of speeding wounded soldiers 90 miles an hour from the front lines to field hospitals. Its springs are synchronized with the patient's heartbeat to avoid increasing fever when traveling over various Terrain. Viewing it in New York August 27, 1941, are left to right: constable Herbert Scott of England, driver; William E. Detlor, whose firm developed the vehicle; M. W. Stand, inspector-general of Civilian Defense, and Maj. Edward Riekert, also. (Photo by AP Photo)

Blankets cover the bodies of a woman (right) and a man (left background) hit by a northbound Penn Central train (background) as they waited with a crowd at Pennsylvania Railroad station in Elizabeth, N.J. on June 8, 1968 to view the southbound train carrying the body of Sen. Robert F. Kennedy to Washington. The woman was identified as Mrs. Antoinette Severini, 54, and the man, John Curia (age unavailable), both of Elizabeth. (Photo by AP Photo)

Britain's Queen Elizabeth, second left, sits next to fashion editor Anna Wintour, third left, and Caroline Rush, chief executive of the British Fashion Council (BFC) as they view Richard Quinn's runway show before presenting him with the inaugural Queen Elizabeth II Award for British Design, as she visits London Fashion Week's BFC Show Space in central London, Tuesday, February 20, 2018. (Photo by Yui Mok/Pool photo via AP Photo)

Blizzard in the High Peak, Derbyshire, by John Finney: “After a difficult journey in the snow, I made my way from Mam Tor down onto the Great Ridge. As the clouds got darker, I placed the tripod and camera at just the right angle to avoid snow getting onto the lens, and used a flash gun and a relatively slow shutter speed to highlight the fast motion of the blizzard”. Classic view, adult class – winner. (Photo by John Finney/Landscape Photographer of the Year)

An installation consisting of a series of bird boxes is displayed in a tree in Duncan Terrace Gardens in Islington on March 24, 2011 in London, England. The boxes by artists Bruce Gilchrist and Jo Joelson of “London Fieldworks”, were designed to reflect the architecture of the Georgian terraces and flats that surround the park in the community gardens. (Photo by Dan Kitwood/Getty Images)