Most of the wall has disappeared, but several sections remain visible. A section near the Museum of London was revealed after the devastation of an air raid on 29 December 1940 at the height of the Blitz. Other visible sections are at St Alphage, and there are two sections near the Tower of London. The River Fleet was canalised after the Great Fire of 1666 and then in stages was bricked up and has been since the 18th century one of London's "lost rivers or streams", today underground as a storm drain.