The Thames Barrier is the world's second-largest movable flood barrier (after the Oosterscheldekering in the Netherlands) and is located downstream of central London. Its purpose is to prevent London from being flooded by high tides and storm surges moving up from the sea.
Its northern bank is in Silvertown in the London Borough of Newham and its southern bank is in the New Charlton area of Charlton in the London Borough of Greenwich.