A glass skywalk in Wanyuan, Sichuan province, built along the side of a cliff, is the highest such skywalk anywhere in China on January 31, 2017. Some visitors have been proven to be terrified by the experience had to brace against the wall in fear. (Photo by Chinanew.com/AsiaWire)

A woman wears VR glasses while the projection mapping is cast on table and walls during its media preview at “TREE BY NAKED, yoyogi park” restaurant in Tokyo, Japan on July 19, 2018. This restaurant incorporates virtual reality, projection mapping, and music to enhance diners' enjoyment of their food. (Photo by Kim Kyung-Hoon/Reuters)

Participants climb over a wall at the “Tough Mudder” endurance event series in Arnsberg September 6, 2014. Competitors who took part in the endurance event saw themselves having to overcome various military style obstacles. (Photo by Ina Fassbender/Reuters)

A rebel fighter carries his weapon as he moves through a hole in a wall in the old city of Aleppo near the frontline against forces loyal to Syria's President Bashar al-Assad December 28, 2014. (Photo by Jalal Al-Mamo/Reuters)

Tourists pose for a selfie in an old American car in front of a wall bearing a graffiti of the Committees for the Defense of the Revolution (CDR) in Havana, on September 27, 2023. September 28 marks the 63th anniversary of the Committees for the Defense of the Revolution (CDR), the so-called “eyes and ears of the Revolution” created by the late Cuban leader Fidel Castro. (Photo by Yamil Lage/AFP Photo)

Soap Bubble Structures by Kym Cox. Bubbles optimise space and minimise their surface area for a given volume of air. This phenomenon makes them a useful tool in many areas of research, in particular, materials science and “packing” – how things fit together. Bubble walls drain under gravity, thin at the top, thick at the bottom, which interferes with travelling lightwaves to create bands of colour. Black spots show the wall is too thin for interference colours, indicating the bubble is about to burst. (Photo by Kym Cox/2019 Science Photographer of the Year/RPS)

Women spray their designs on a wall during a graffiti class offered by the LATA 65 organization in Lisbon, Portugal May 14, 2015. The LATA 65 organization is an initiative for the elderly in the area of urban art. Since it began in 2012, they have introduced the world of graffiti to over 100 senior citizens, giving workshops in different neighborhoods of Lisbon. (Photo by Rafael Marchante/Reuters)

Street art started out as unintelligible words written on concrete walls with spray paint by gang members or silly kids. Now, however, it evolved into a unique form of art that might stun and inspire awe in the onlookers. For example, the artist that goes by the name 1010 specializes in creating optical illusions. His creations look like portals into other dimensions, without any hint that it might simply be a flat concrete wall painted over with multicolored paints. These pieces of art are so good that it is hard not to reach out into these ‘holes’ to find out whether or not they are real. (Photo by 1010)