text: The O2 Arena, commonly known as The O2, is a multi-purpose indoor arena in the centre of The O2 entertainment district on the Greenwich Peninsula in southeast London. It opened in its present form in 2007. It has the third-highest seating capacity of any indoor venue in the United Kingdom, behind the Co-op Live and Manchester Arena, and in 2008 was the world's busiest music arena. As of 2022, it is the ninth-largest building in the world by volume with a diameter of 365 metres (399 yards) and a height of 52 metres (57 yards).
  The arena was built under the Millennium Dome (renamed The O2), a large dome-shaped building built to house an exhibition celebrating the turn of the third millennium; as the structure still stands over the arena, The Dome remains a name in common usage for the venue. The arena, as well as the overall The O2 complex, is named after its primary sponsor, the telecommunications company O2, a subsidiary of Virgin Media O2.