There are several signs from the Second World War located in the Lord North Street in Westminster. They refer to underground shelters.
Air raid shelters were built specifically to serve as protection against enemy air raids. However, pre-existing edifices designed for other functions, such as Underground stations (tube or subway stations), tunnels, cellars in houses or basements in larger establishments, and railway arches, above ground, were suitable for safeguarding people during air raids.
A commonly used home shelter was known as the Anderson shelter which would be built in a garden and equipped with beds as a refuge from air raids.