As of 2021, which of the following is the tallest Ferris wheel?

Ain Dubai is the world's largest and tallest observation wheel located on Bluewaters Island, near the Dubai Marina in Dubai, United Arab Emirates

Ain Dubai in the United Arab Emirates is 250-metre (820 ft). It opened to the public on 21 October 2021 and is currently the world's tallest Ferris wheel in operation.

Construction began in May 2015 anticipating completion in early to mid-2019. Further delays pushed the target opening to October 20, 2020, in order to coincide with Expo 2020, but this itself was postponed due to the COVID-19 pandemic. The wheel opened a year later on October 21, 2021.

Ain Dubai is taller than the previous world's tallest observation wheel, the 167.6 m (550 ft) High Roller, which opened in Las Vegas in March 201.