Billingsgate Fish Market is a large market in Poplar and is the United Kingdom's largest inland fish market. It takes its name from Billingsgate, a ward in the south-east corner of the City of London, where the riverside market was originally established. In its original location in the 19th century, Billingsgate was the largest fish market in the world and is close to Canary Wharf and Blackwall.
More information on the Wikipedia page [1]. The website is [2].