City of London's 'ring of steel'

The ring of steel is the popular name for the security and surveillance cordon surrounding the City of London, installed to combat IRA and other terrorist threats. Roads entering the city are narrowed and have small chicanes to force drivers to slow down and be recorded effectively on CCTV cameras. These roads typically have a paved strip down the middle with a sentry box where policemen can stand guard and monitor traffic.

The measures were introduced following massive IRA bombs in the City in the early 1990s (see for example Baltic Exchange bombing). At this time the sentry posts were guarded by armed police almost continuously. Following IRA ceasefires the police presence was curtailed. Following the September 11th terrorist attacks, and a reported increased terrorist threat to the United Kingdom, security has been stepped up again somewhat, with occasional spot checks on vehicles entering the cordon, although not to previous levels.

The boundary of the London borough of the City of London corporation is also marked by statues of griffins which vary in size and colour, but all carry the City's coat of arms.