Between Saturday 27 May and Monday 29 May, installation of signalling equipment on the tracks approaching London Bridge will affect Southeastern services.
There will be no trains to or from Charing Cross, Waterloo East or London Bridge. Trains will be diverted to alternative London stations.
On Sunday 28 May, engineering work is taking place to install new sets of points, which allow trains to cross from one track to another, on the Thameslink route between Farringdon and Loughborough Junction.
No trains will run between London St Pancras International and Elephant & Castle.
Further signalling work will also affect Southern services on all three days of the bank holiday.
Buses will replace trains between West Croydon and Epsom Downs.
Work in the Redhill area will mean no trains between Purley to Horley via Redhill, Reigate to Gatwick Airport via Redhill, and Redhill to Edenbridge.
Meanwhile, Crossrail is continuing to erect its overhead line power supply in the Abbey Wood area, meaning no trains between Plumstead and Slade Dartford on Sunday and Monday.
Alternatively, you can follow our engineering work on Twitter using the hashtag #SpringBHworks