London Bridge station opened in 1836. It is the oldest terminus in the capital and is showing its age.
Some 50 million journeys start or end at the station every year, making it the fourth busiest station in the UK.
There are long queues in the rush hour and crowded platforms.
London Bridge is also a major bottleneck for trains because of the way the routes cross one another north and south of the station.
The final phase of the Thameslink Programme will see London Bridge station completely redeveloped. There will be an entirely new concourse, more space for passengers, better interchange between trains, buses and other forms of transport, and more capacity for longer more frequent trains to use the station.