Greenwich (pronounced 'gren-itch' [ˈgrɛnɪtʃ], or [ˈgrɪnɪtʃ] by the locals) is a town, now part of the south eastern urban sprawl of London, on the south bank of the river Thames in the London Borough of Greenwich.
Greenwich Mean Time was at one time based on the time observations made at the Royal Greenwich Observatory, before being superseded by Coordinated Universal Time.
While Greenwich no longer hosts a working astronomical observatory, a ball still drops daily to mark the exact moment of 1pm (13:00), and there is a good museum of astronomical and navigational tools.
Covent Garden market moved out of its central location to the wastes of Vauxhall years ago, to be replaced by a tourist-orientated market; Billingsgate, the fish market famous for the bad language of its traders has moved to the Isle of Dogs, and the original waterside building been taken over by city businessmen.
For the general markets, the earlier you visit a market the better chance you have of a bargain: grubbing around with a torch as a stallholder opens 04:00 is the norm.
Antiquesmarket, famous for once being where thieves could sell their goods with impunity (a royal licence meant that stolen goods bought here did not have to be returned) which has suffered somewhat since that privilege was withdrawn.