Close to 20 of these permanent structures tower 100m or more into the air and have the capacity to carry as many as 10,000 passengers a day.
And by the way, they don't give "rides" - they take you on a "flight".
Inevitably more wheels are rolling in with plans reported afoot in Beijing, Berlin, Dubai and New York, among other world cities.
A relative baby - at about 60m - is due to open in Washington DC this month. The Capital Wheel will reveal new views of the Capitol, the White House and the Pentagon.
The biggest of the lot is Las Vegas' High Roller - which towers 167.6m over the strip. At any one time, it can carry up to 1120 passengers.
When the High Roller opened in March, it passed the Singapore Flyer - built in 2008 and the equivalent of 42 storeys high at a towering 165m - for the title world's largest wheel.
The one-complete-circuit, half-hour flight in one of its 28 enclosed capsules provides expansive panoramas of Singapore, the nearby Gardens by the Bay and the dozens of ships anchored offshore while they wait for a berth in the city's harbour. "Flyers" can move around inside the capsule to get the best view for photo opportunities.
And the experience is not limited to just the flight - the entertainment complex includes a 3D multimedia presentation about the flyer and Singapore itself, a wide range of dining and shopping options and even a flight simulator where budding aviators can try their hand as the captain-in-command of a 737 aircraft.
The London Eye is credited with being the forerunner of similar attractions that have popped up around the world in the last 15 years. At 135m tall it was the biggest until a 160m wheel was built in China in 2006. It takes around 30 minutes for a full circle transit - and with it brings new perspectives of London's familiar landmarks, such as Buckingham Palace, Big Ben, the Thames and further afield - depending on the day's visibility.