Romford Market
Romford Market is a large outdoor retail market located in Romford in the London Borough of Havering, England. The market right was established by royal order in 1247. Rival markets are prohibited within 6.66 miles (10.72 km). Governance of the market was strengthened by the 1465 charter of the Liberty of Havering, which was administered from a court house at the western end of the market. Formerly a livestock and agricultural market, cattle was last sold in 1958. The market has been in local authority ownership since it was purchased by the Romford Local Board in 1892 and is now owned by Have

Romford Market is a large outdoor retail market located in Romford in the London Borough of Havering, England. The market right was established by royal order in 1247. Rival markets are prohibited within 6.66 miles (10.72 km). Governance of the market was strengthened by the 1465 charter of the Liberty of Havering, which was administered from a court house at the western end of the market. Formerly a livestock and agricultural market, cattle was last sold in 1958. The market has been in local authority ownership since it was purchased by the Romford Local Board in 1892 and is now owned by Have
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