A New York window cleaner strapped to the side of The RCA Building in the Rockefeller Center, with St Patrick's Cathedral below him to the left. (Photo by William Lovelace/Express/Getty Images). 2nd May 1961

Lake Baikal is the world's oldest lake, at 25 million years (possibly older), and deepest, averaging 744.4 metres (2,442 ft).

Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the world, containing roughly 20% of the world's unfrozen surface fresh water.

Window washers from the American National Skyline company (from left to right in the image below: Jordan Emerson, Steve Oszaniec and Danny Oszaniec) suit up as Marvel Comics superheroes to pleasantly surprise the children (who are patients) and their families inside as the dressed up crew cleans the outside of the windows at Le Bonheur Children’s Hospital in Memphis

“Getting to see girls’ bedrooms must have been a teenage obsession for the members of the all-male photographic collective Riverboom. Now that they have more or less grown up, they have decided to transform that dream into a reality. Riverboom’s Gabriele Galimberti and Edoardo Delille are traveling the five continents to see where girls, between the ages of 18 and 30, sleep. They have discovered that girls’ bedrooms are much more then just places where they lay down their heads – they are the places where girls read, love, dream, work and play”. – Gabriele Galimberti. Photo: Katerinai, 27 – Athens, Greece. (Photo by Gabriele Galimberti/Riverboom Ltd)

General view of a Saks Fifth Avenue Holiday shopping window display on November 30, 2015 in New York City. (Photo by Michael Loccisano/Getty Images)

Images created with Post-it notes are seen in the windows of offices at 75 Varick Street in lower Manhattan, New York, U.S., May 18, 2016, where advertising agencies and other companies have started what is being called a “Post-it note art war” with employees creating colorful images in their windows with Post-it notes. (Photo by Mike Segar/Reuters)

Japan's computer giant Fujitsu employee displays the world's first personal computer with Intel's RealSense 3D camera “FMV Esprimo” in Tokyo on October 9, 2014. The new desktop PC with 23-inch LCD display can make avatars which mimic the user's look and motion for chatting on the Internet. (Photo by Yoshikazu Tsuno/AFP Photo)