The Millennium Dome 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 political and attracted barely half of the 12 million customers its sponsors forecasted, and so were deemed a failure by the press. All the original exhibition elements were sold or dismantled. In a 2005 report, the cost of the Dome and surrounding land (which increased to 170 acres from the initial offering of the 48 acres enclosed by the Dome) and managing the Dome until the deal was closed was £28.7 million. The value of the 48 acres occupied by the Dome was estimated at £48 million, which could have been realised by demolishing the structure, but it was considered preferable to preserve the Dome. The structure itself still exists and is now a key exterior feature of The O2. The Prime Meridian passes the western edge of the Dome and the nearest London Underground station is North Greenwich on the Jubilee line. Architecture The dome is one of the largest of its type in the world. Externally, it appears as a large white marquee with twelve yellow support towers, one for each month of the year, or each hour of the clock face, representing the role played by Greenwich Mean Time. In plan view it is circular, ( for each day in a standard year) in diameter. It has become one of the United Kingdom's most recognisable landmarks, and can be easily identified on satellite images of London. Its exterior is reminiscent of the Dome of Discovery built for the Festival of Britain in 1951. The architect was Richard Rogers and the contractor was a joint venture company, McAlpine/Laing Joint Venture (MLJV) formed between Sir Robert McAlpine and Laing Management. The building structure was engineered by Buro Happold, and the entire roof structure weighs less than the air contained within the building. Although referred to as a dome it is "not a dome in the structural sense [...] In this building, a dome-shaped cable network is supported on a ring of [...] masts". It has been disparagingly referred to as the