This was the original name of the large dome-shaped building on the Greenwich Peninsula in South East London, England, which housed a major exhibition celebrating the beginning of the third millennium. As of 2022, it is the ninth largest building in the world by usable volume. The exhibition was open to the public from 1 January to 31 December 2000. The project and exhibition were highly contentious and attracted barely half of the 12 million customers its sponsors forecasted, and so were deemed a failure by the press.