Maintenance engineer Darren Unsworth cleans one of the crystal Edwardian chandeliers that illuminate Blackpool Tower Ballroom on January 16, 2012 in Blackpool, England. Blackpool's famous Tower Ballroom is undergoing an annual spring clean which includes lowering the ornate chandeliers where each shard of crystal is cleaned for the coming season of dancing. The dance floor consisting of 30,602 blocks of mahogany, oak and walnut is also sanded and polished to give the perfect dance floor. (Photo by Christopher Furlong/Getty Images)

Marcos Trujillo cleans the engines of a boat made by Contender in preparation for tomorrow's opening day of the four day long Progressive Insurance Miami International Boat Show at the Miami Beach Convention Center on February 15, 2012 in Miami Beach, Florida. The boat show features more than 3,000 boats and 2,000 exhibitors from all over the globe. (Photo by Joe Raedle/Getty Images)

The giant metal structure sits 330ft above the ground on the roof of a 22 storey office block in Dutch capital Amsterdam on September 6, 2016. Tourists sit in a playground-style chair as they propel themselves them over the edge of the building with only thin-air between them and the ground below. Engineers spent several years designing and building the breathtaking swing. By being fixed to the top of a building it reaches new heights – dwarfing other swings around Europe but trailing behind the 1,150ft high mechanical rides at the Stratosphere Hotel in Las Vegas, Nevada. (Photo by Huub Zeeman/SWNS.com)

A model in Mongolia costumes prepares backstage in Xiangshawan Desert, also called Sounding Sand Desert on July 18, 2013 in Ordos of Inner Mongolia Autonomous Region, China. Xiangshawan is China's famous tourist resort in the desert. It is located along the middle section of Kubuqi Desert on the south tip of Dalate League under Ordos City. Sliding down from the 110-metre-high, 45-degree sand hill, running a course of 200 metres, the sands produce the sound of automobile engines, a natural phenomenon that nobody can explain. (Photo by Feng Li)

Wang Jiayun, born June 18 1993. Wang’s height is 164cm, her weight 42kg. Wang Jiayun says she was born in Kowloon of Hong Kong Special Administrative Region, and presently lives in Shenzhen City of Guangdong province in China. Identity: High school student. Wang's large eyes, pale face, perfectly structured nose and extremely slim figure resemble a brand of human-sized blow-up doll popular with Korean men. This cute and s*xy barbie doll look a like is hot property. She recently became the No.1 searched name in the country's top search engine, Naver.com. Photo: Wang Jia Yun (王嘉韻 or 왕지아인). (Photo by Wang Jia Yun)

“A monowheel is a one-wheeled single-track vehicle similar to a unicycle. However, instead of sitting above the wheel, the rider sits either within it or next to it. The wheel is a ring, usually driven by smaller wheels pressing against its inner rim. Most are single-passenger vehicles, though multi-passenger models have been built.

Pedal-powered monowheels were built in the late 19th century; most built in the 20th century have been motorized. Some modern builders refer to these vehicles as monocycles, though that term is also sometimes used to describe motorized unicycles. Today, monowheels are generally built and used for fun and entertainment purposes, though from the 1860s through to the 1930s, they were proposed for use as serious transportation”. – Wikipedia

Photo: Cycle inventor Kerry McLean poses for the photographer 2000 in Walled Lake, Michigan. The “Monocycle” is equipped with a 40-horsepower engine, 4ft tire and is expected to reach speeds upwards of 100 mph. (Photo by Bill Pugliano/Liaison)

Lukas Michul, a member of the “dream walker” group jumps from atop the rugged rocks overlooking the azure waters of Navagio beach, one of the Greece's most renowned leisure spots on the popular tourist island of Zakynthos on June 23, 2014. This is rope jumping – part diving, part rock climbing, with a touch of engineering. The aim of the project is to dream jump in 80 places with most ravishing nature and architecture all over the world .They plan to stage their next leaps at a cave complex in Croatia, a French viaduct, skyscrapers in Las Vegas and Johannesburg, and the Grand Canyon. (Photo by Louisa Gouliamaki/AFP Photo)

In this Wednesday, May 13, 2015 photo, a Nepalese laborer carries a load of bricks at a brick factory in Bhaktapur, Nepal. Almost 745,600 buildings and homes have been damaged or destroyed, including at least 87,700 in the capital, according to Nepal's emergency authority. Engineers say only 40 percent of Kathmandu's damaged buildings as habitable. (Photo by Bernat Amangue/AP Photo)