By Docklands Light Railway (Dlr)
This automated rail system runs from central London terminals at Tower Gateway adjacent to the Tower of London and Bank with interchange to the London Underground. Catch a train bound for Lewisham and get off at Cutty Sark station in the town centre. Because there is no driver and most of the route is elevated, you get a great view from the front of the passing city. Travelcards valid.
By Tube
North Greenwich tube station is not recommended as it is a bus ride away from Greenwich town centre and was built specifically for access to the Millennium Dome now the O2 Arena. However, it is possible to walk from here along the Thames Path to Greenwich town centre, it is a bleak but peaceful industrial landscape and it will take about 45 minutes.
By ship
Several companies run river tour boats from central London piers at Westminster Bridge, the Millennium Wheel and the Tower of London, to Greenwich Pier which is adjacent to Greenwich town centre and within walking distance of the all the main attractions. £6-8; 33% discount to Travelcard holders.
Thames Clippers (http://www.thamesclippers.com) commuter service offers an infrequent service, but is quicker and better value £4.55, 33% off for Travelcard holders.