Greece's Maria Sakkari reacts during her women's singles quarter-final tennis match against Poland's Iga Swiatekon Day 11 of The Roland Garros 2021 French Open tennis tournament in Paris on June 9, 2021. (Photo by Gonzalo Fuentes/Reuters)

Kubra Korkut of Turkey in action against Viktoriia Safonova of the Russian Paralympic Committee during Class 7 Group B Women's Singles Table Tennis Match on day 2 of the Tokyo 2020 Paralympic Games at Tokyo Metropolitan Gymnasium on August 26, 2021 in Tokyo, Japan. (Photo by Ivan Alvarado/Reuters)

Karen Khachanov serves to Carlos Alcaraz of Spain during the Men's Singles Quarter-Final match on Day Ten of the Mutua Madrid Open at La Caja Magica on May 03, 2023 in Madrid, Spain. (Photo by Julian Finney/Getty Images)

Belarus' Aryna Sabalenka poses with the 2023 Australian Open winner's trophy in Royal Botanic Garden in Melbourne on January 29, 2023, following her victory over Kazakhstan's Elena Rybakina in the women's singles final of the tennis tournament. (Photo by Carl Recine/Reuters)

Toyota Motor unveils a concept car the “PM”, is on display at a press preview for the Tokyo Motor Show in Makuhari, east of Tokyo October 23, 2003. PM is a single seater personal vehicle whose cabin posture changes from upright to reclined as speed increases. (Photo by Koichi Kamoshida/Getty Images)

“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)

Flamengo soccer fans cheer a goal scored by Gabriel against Argentina's River Plate in the Copa Libertadores final match, broadcast on a giant screen at a watch party at the Macarena Stadium, in Rio de Janeiro, Brazil, Saturday, November 23, 2019. The first single-match final will be played in front of more than 65,000 fans at Lima’s Monumental Stadium. The match was originally scheduled for Santiago’s National Stadium, but it was moved because of street protests in Chile. (Photo by Silvia Izquierdo/AP Photo)

In this image released by World Press Photo, Thursday April 15, 2021, by Ami Vitale for CNN, titled Rescue of Giraffes from Flooding Island, which won the first prize in the Nature Singles category, shows A Rothschild's giraffe (Giraffa camelopardalis rothschildi) is transported to safety in a custom-built barge from a flooded Longicharo Island, Lake Baringo, in western Kenya, on Dec. 3, 2020. (Photo by Ami Vitale for CNN, World Press Photo via AP Photo)