In this October 16, 2014 photo, a man cleans his American classic car before going to work in Havana, Cuba. While the U.S. embargo that took effect in 1961 stopped the flow of new cars, and most parts, a few Cubans now manage to bring in replacement parts when friends or family visit from the U.S. (Photo by Franklin Reyes/AP Photo)

An Iraqi special forces soldier shot dead an Islamic State suicide bomber in Mosul, Iraq March 3, 2017. (Photo by Goran Tomasevic/Reuters)

Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)

Seized plastic handguns which were created using 3D printing technology are displayed at Kanagawa police station in Yokohama, south of Tokyo, in this photo taken by Kyodo May 8, 2014. Yoshimoto Imura became the first man to be arrested in Japan for illegal possession of two guns he created himself using 3D printing technology, Japanese media said on Thursday. The 27-year-old, a college employee in the city of Kawasaki, was arrested after police found video online posted by Imura claiming to have produced his own guns. Gun possession is strictly regulated in Japan. Police raided Imura's home and found five guns, two of which could fire real bullets, Japanese media said. (Photo by Reuters/Kyodo)

People play "Palin", a traditional ritual and ancestral Mapuche game played with curved sticks called "Chuecas" and a wooden ball, during a meet on Dia de la Raza (Day of the Races), also known as Columbus Day in Vina del Mar, Chile October 11, 2015. (Photo by Rodrigo Garrido/Reuters)

Boys play with a drainage culvert used for flood control in Las Pinas, Metro Manila February 28, 2016. (Photo by Erik De Castro/Reuters)

“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)

A woman views a painting by American artist George Condo entitled “Jesus” on October 17, 2011 in London, England. (Photo by Oli Scarff/Getty Images)