The modernisation of Bank Tube station has reached a landmark stage, with over half of the construction work now complete.
Most of the construction works have been completed in isolation from the existing station to keep disruption to customers to a minimum.
The station complex including both Bank and Monument is one of the busiest on the network, with over 120 million customers passing through it each year.
When the project is complete in 2022, there will be a new tunnel for the southbound Northern line, allowing the existing platform to be converted into a new customer concourse in order to reduce overcrowding.
The new tunnel has been excavated under an incredibly complex part of London, with 31 listed buildings bordering the project.
Over 200,000 tonnes of material has already been excavated - equivalent to around 16,000 New Routemaster buses.
TfL is constructing a new station entrance on Cannon Street which will provide two new lifts in order to introduce step-free access from the street to the Northern line and improve step-free access to the DLR.
The addition of 12 new escalators and two moving walkways will also make customer journeys quicker and more comfortable.
The new tunnel has been excavated, with waterproofing and concrete lining now underway.
The escalator barrel from the new entrance on Cannon Street to the Northern line platforms is complete and another that will form a new escalator to the Central line is nearing completion.
As well as the progress being made underground, the new station on Cannon Street is beginning to take shape.
The structure for the new station will be complete this summer, allowing interior wall construction and station fit out to start in the autumn.
The cross passages to the new Northern line tunnel are also well underway, with a new 'secret door' already visible to customers using the existing southbound platform.
The new tunnel will be connected to the existing Northern line in 2021.
Stuart Harvey, TfL's Director of Major Projects, said: 'The upgrade of Bank Tube station is a crucial project that will make journeys through a vital interchange much easier and more comfortable.
'These pictures show the extent of the great work being done by TfL staff and contractors as we continue to make good progress on delivering these improvements for Londoners.'
Demand at Bank has risen by around a quarter in recent years. Around 120,000 customers use the station every weekday morning, of which over 50,000 are changing to another line.
A new entrance to the Waterloo & City line on Walbrook opened in December 2018, helping to relieve congestion for customers using that line and providing quicker access from the City.
The added capacity will make a significant positive impact to hundreds of thousands of people each day.