I just bought a unicycle, a vehicle that touches down with just the one wheel.
I have ridden a unicycle. It looks so hard to do.
It is not easy.  I wanted one after watching the pros at circuses, festivals and street performers.
Oh that must have been pretty cool. Who invented the unicycle?
trials.
History.
US patents for single-wheeled 'velocipedes' were published in 1869 by Frederick Myers and in 1881 by Battista Scuri.
Unicycle design has developed since the Penny Farthing and later the advent of the first unicycle into many variations including: the seatless unicycle ("ultimate wheel") and the tall ("giraffe") unicycle. During the late 1980s some extreme sportsmen took an interest in the unicycle and modified unicycles to enable them to engage in off-road or mountain unicycling, trials
Unicycle
A unicycle is a vehicle that touches the ground with only one wheel. The most common variation has a frame with a saddle, and has a pedal-driven direct drive. A two speed hub is commercially available for faster unicycling. Unicycling is practiced professionally in circuses, by street performers, in festivals, and as a hobby. Unicycles have also been used to create new sports such as unicycle hockey. In recent years, unicycles have also been used in mountain unicycling, an activity similar to mountain biking or