London hosts Great British Beer Festival The Great British Beer Festival has turned London's Olympia exhibition hall into the biggest pub in the world, serving an expected 55,000-plus punters over five days until Saturday. The event is staged by CAMRA, the Campaign for Real Ale, which says pubs are closing at a worsening rate -- currently 31 a week -- and being turned into supermarkets and estate agencies. IMAGES AND SOUNDBITES