The Enigma coding machine used by the Germans in WWII on display at Bletchley Park National Code Centre, November 25, 2004 in Bletchley, England. (Photo by Ian Waldie/Getty Images)

Cha Huilan, a 40-year old Lisu woman, and her daughter leave Lazimi village with a zipline across the Nu River in Nujiang Lisu Autonomous Prefecture in Yunnan province, China, March 24, 2018. Chinese mountain villagers, cut off from shops and churches by a raging river, use a zipline to cross its violent rapids and jagged rocks. (Photo by Aly Song/Reuters)

This cable ropeway suspended between cliffs is the only access to Yushan village in Hubei Province, Chin, which has a population of just over 200 people. The ropeway was built in 1997; before that villagers faced a walk of several days to get to the next nearest village. The ropeway, which is powered by a diesel engine, is 1,000 metres long and 400 metres above the valley floor.

In a July 14, 1967 file photo, left, National Guardsmen make their way along Market Street in Newark, N.J, after an evening of deadly rioting and looting in what came to be known as the Newark riots. In a June 16, 2017 photo, right, an ambulance drives on the same block 50 years later. (Photo by AP Photo/File, left; Julio Cortez, right)

Marco Fiera from NoFit State Circus tries out the SkyWire, the new zip wire attraction which opens to the public this week at The Eden Project on July 17, 2012 in St Austell, England. The new 740m zip wire, currently the longest in England, allows the public a bird's eye view of the iconic Rainforest and Mediterranean Biome structures as well as the Cornish attractions outdoor gardens. The Eden Project – which opened in 2001 and has attracted over one million visitors – showcases 100,000 plants from around the world in two giant transparent domes, one of which is the world's largest greenhouse, each recreating different climate conditions. (Photo by Matt Cardy)

A model presents a creation by LARHHA during the Code'41 Andalusian Fashion Week at the Amphitheatre of Italica in Seville on March 21, 2021. (Photo by Cristina Quicler/AFP Photo)

A German Shepard bares its teeth during Schutzhund attack dog training at Witmer-Tyson Imports February 14, 2002 in Newark, CA. (Photo by Justin Sullivan/Getty Images)