Queenhithe
Queenhithe is a small and ancient ward of the City of London, situated by the River Thames and to the south of St. Paul's Cathedral. The Millennium Bridge crosses into the City at Queenhithe.

Queenhithe is a small and ancient ward of the City of London, situated by the River Thames and to the south of St. Paul's Cathedral. The Millennium Bridge crosses into the City at Queenhithe.
Check the official site before travelling; hours and prices can change.
More bridges

Tower Bridge
The bridge people mean when they say London Bridge. Walk the high-level walkway for the glass floor.

Millennium Bridge
Foot-only suspension bridge from St Paul's to Tate Modern — the only crossing aligned on St Paul's dome.

Hammersmith Bridge
Currently pedestrian-only, Victorian wrought-iron beauty — best photographed at golden hour.
Source: wiki-list