Popularly known as 'The Drain', the Waterloo & City Line has reopened today (Monday 7 June) at short notice.

  The 1.5 mile link under the Thames connects Waterloo and Bank stations.  It has been closed since March last year.

The Waterloo & City Line will run every 5min Monday to Friday from 06:00–10:00 in the morning and 15:30–19:00 in the afternoon.

Built in 1898, and London’s second electric railway in absolute terms, it is the least-used Tube line, carrying in normal years over 15m passengers annually. However, in terms of the average number of journeys per mile it is the second-most intensively-used line behind the Victoria line.

Bank, the most complex of all London Underground, is presently undergoing a major re-build with the Northern line expected to close for several months later this year.  The Central Line is part of what is a multiplex of lines including the DLR and at The Monument site, the Circle Line and District Line.

https://tfl.gov.uk