The O2 arena, visually typeset in branding as The O2 arena, is a multi-purpose indoor arena located at the centre of The O2, a large entertainment complex on the Greenwich peninsula in South East London, United Kingdom. With a capacity of up to 23,000 depending on the event, it is one of the largest indoor arenas in Europe alongside the MEN Arena in Manchester, the Lanxess Arena in Cologne and the Belgrade Arena in Belgrade. In 2008, The O2 arena took the crown of the World's Busiest Arena from the MEN Arena, a title which it had held since 2001.