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. Some roads have been closed to traffic entirely. Despite the term 'ring of steel' the roadblocks and chicanes are actually created with concrete blocks, sometimes plastic coated, which are wedged together. Surveillance is close monitoring of behaviour. ... This article is about a small section of central London. ... There are several paramilitary groups which claim or have claimed the title Irish Republican Army (IRA) and advocate a unitary Irish state with no ties to the United Kingdom. ... Terrorism is a controversial term with multiple definitions. ... A chicane is a sequence of tight serpentine curves in a roadway, used in auto racing and on city streets to slow cars. ... Closed-circuit cameras are often used to discourage crime Closed-circuit television (CCTV), as a collection surveillance cameras doing video surveillance, is the use of television cameras for surveillance. ...

The measures were introduced following massive IRA bombs in the City in the early 1990s (see for example the 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 Baltic Exchange is a UK company that operates the premier global marketplace for shipbrokers, ship owners, and charterers. ... The World Trade Center on fire The September 11, 2001 attacks were a series of coordinated terrorist attacks against the United States on September 11, 2001. ...

The boundary is also marked by statues of griffins which vary in size and colour, but all carry the City's coat of arms. Roman griffon, Turkey The griffin (also spelled gryphon, griffon or gryphin) is a legendary creature with the body of a lion, the head of an eagle and the ears of a horse or a donkey. ... A modern coat of arms is derived from the medi val practice of painting designs onto the shield and outer clothing of knights to enable them to be identified in battle, and later in tournaments. ...

See also

• Mass surveillance
• UK topics