HMS Belfast is a gunship of 11,000 tons, commissioned in 1939, which saw active service in the Second World War. Since then it has been moored on the south bank of the Thames, in postcard-land, between Tower Bridge and London Bridge, opposite the Tower of London. From its deck one can see St. Paul's Cathedral and the gilt top of the columnlike Monument to the Great Fire of London erected, as so much of London was erected, by Christopher Wren. The ship serves as a floating museum, as a memorial, as a training ground.