AO Arena

The Manchester Arena, known as the AO Arena for sponsorship reasons, is an indoor arena in Manchester, England, immediately north of the city centre and partly above Manchester Victoria station in air rights space. The arena has the highest seating capacity of any indoor venue in the United Kingdom, and the second largest in Europe with a capacity of 21,000

The arena is one of the world's busiest indoor arenas, hosting music and sporting events such as boxing and swimming. The arena was a key part of Manchester's bids to host the Olympic Games in 1996 and 2000 and was eventually used for the 2002 Commonwealth Games.

Source: Wikipedia