Walthamstow Market
Walthamstow Market, in the London Borough of Waltham Forest, is the second longest outdoor market in Europe, the longest being the Porta Portese in Rome, which is 2 km long. It occupies all but the last 100 metres (330 ft) of Walthamstow's High Street. It is reputed to be a mile long, but in fact measures approximately one kilometre.
Walthamstow Market, in the London Borough of Waltham Forest, is the second longest outdoor market in Europe, the longest being the Porta Portese in Rome, which is 2 km long. It occupies all but the last 100 metres (330 ft) of Walthamstow's High Street. It is reputed to be a mile long, but in fact measures approximately one kilometre.
Check the official site before travelling; hours and prices can change.
More markets
Borough Market
London's defining food market — go early Saturday, eat your way around the perimeter.
Columbia Road Flower Market
Sunday-only flower market in the East End — 8 a.m. for choice, 2 p.m. for prices.
Maltby Street Market
Borough's smaller, scruffier sibling — railway arches, weekend only.
Source: wiki-list