“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)

Matthias Broda, inventor and designer of the wooden e-bike, cycles a prototype along a street in Berlin, November 20, 2014. The wooden e-bike produced by German company Aceteam from ash wood, will be launched on the market by spring 2015 and will cost around 3,950 euro (4,950 dollars). The e-bike will be equipped with an 250W e-bike motor for a range of up to 100 kilometer (62 miles) with a rechargeable battery. (Photo by Fabrizio Bensch/Reuters)

March 11, 2008 Swiss car manufacturer Rinspeed made quite the splash at the Geneva Motor Show with its innovative sQuba, a fully functional submersible concept car that cost $1.5 million to build. (Photo by Rinspeed)

Tao Xiangli gets out of his homemade submarine after operating it in a lake on the outskirts of Beijing September 3, 2009. Amateur inventor Tao, 34, made a fully functional submarine, which has a periscope, depth control tanks, electric motors, manometer, and two propellers, from old oil barrels and tools which he bought at a second-hand market. He took 2 years to invent and test the submarine which costs 30,000 yuan ($4,385). (Photo by Christina Hu/Reuters)

In this October 21, 2015, file photo, a young man rides a hoverboard along a Manhattan street toward the Empire State Building in New York. More than 500,000 hoverboards are being recalled after reports that they can burst into flames. The Consumer Product Safety Commission said Wednesday, July 6, 2016, it has received 99 reports of battery packs in the two-wheel motorized scooters catching fire or exploding that causing burns or property damage. The recalled hoverboards were made by eight companies. (Photo by Kathy Willens/AP Photo)

Balinese Hindu people take part in a cleansing ceremony called “Melasti”, in Denpasar, Bali, Indonesia, 25 March 2025. Melasti is a purification ritual where Balinese Hindus cleanse themselves and their sacred objects in the ocean to purify and renew spiritually, symbolizing the washing away of impurities and starting anew. It typically precedes Nyepi, the Day of Silence, marking the Balinese New Year. Balinese will celebrate Nyepi Day on 29 March 2025, during which Hindus on the island of Bali are not allowed to travel, work, light lamps, cook, or do any other activities. (Photo by Made Nagi/EPA)

A racoon jumps over a fence in almost deserted Central Park in Manhattan on April 16, 2020 in New York City. Gone are the softball games, horse-drawn carriages and hordes of tourists. In their place, pronounced birdsong, solitary walks and renewed appreciation for Central Park's beauty during New York's coronavirus lockdown. The 843-acre (341-hectare) park – arguably the world's most famous urban green space – normally bustles with human activity as winter turns to spring, but this year due to Covid-19 it's the wildlife that is coming out to play. (Photo by Johannes Eisele/AFP Photo)

Talbot Lago T26 Grand sport SWB Saoutichik is displayed for auction during the Retromobile show in Paris, Tuesday, February 3, 2015. 60 rusting motors, which include a vintage Ferrari California Spider, a Bugatti and a very rare Maserati, were found gathering dust and hidden under piles of newspapers in garages and outbuildings at a property in France. The cars were collected from the 1950s to the 1970s by entrepreneur Roger Baillon, who dreamt of restoring them to their former glory and displaying them in a museum, but, his plans were dashed as his business struggled, forcing the sale of about 50 vehicles, to be auctioned off on Feb. 6. (Photo by Jacques Brinon/AP Photo)