Zookeepers measure the length of a pueblan milk snake in the Reptile House of ZSL London Zoo as part of their annual weighing and measuring of their animals on August 25, 2011 in London, England. The heights and weights of over 750 different animal species at the zoo are recorded into the International Species Information System, to monitor their health and share the data with other zoos across the world. (Photo by Oli Scarff/Getty Images)

A stunt rider performs on the wooden wall during a fair in Bogra, Bangladesh, February 10, 2021. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

Iranian artist and designer Mehdi Ghadyanloo, with the help of the municipality, is slowly brightening up the city of Tehran one wall at a time. The 33-year old street artist has been painting murals and walls in Tehran for the last 5 years age, during which he’s reported to have painted over one hundred walls.

Fearless daredevils clamber up the worlds highest man-made climbing wall – running up the face of a 540ft dam. The Diga di Luzzone in Switzerland is considered by climbers as the Everest of wall climbing. (Photo by Ilana Marcus/Caters News)

Mount Sinabung releasing volcanic ash, on February 04, 2017 Karo, North Sumatra, Indonesia. (Photo by Albert Damanik/Barcroft Images)

A man passes by a wall with graffiti in Beirut, Lebanon, on May 29, 2019. (Photo by Bilal Jawich/Xinhua News Agency/Alamy Live News)

A woman walks past a mural on a wall along a street in Singapore on February 17, 2021. (Photo by Roslan Rahman/AFP Photo)

People climb on an artificial ice-wall in Liberec, about 100 km north of Prague, Czech Republic, Saturday, January 23, 2015. The wall was prepared in a former quarry just near the centre of the city. (Photo by Radek Petrasek/CTK via AP Photo)