Starfish sites were large-scale night-time decoys created during the Blitz to simulate burning British cities. The aim was to divert German night bombers from their intended targets so they would drop their ordnance over the countryside. The sites were an extension of Colonel John Turner's decoy programme for airfields and factories (code named "Q" Sites). Following the bombing, and near destruction, of Coventry in November 1940, Turner was tasked with creating decoys for seven major cities.
Turner referred to the new sites as "Special Fire" or "SF". However, one early site (near Bristol) was given the name "Starfish", which subsequently became used for all of the decoys. The sites were constructed around 4 miles (6.4 km) from their protection target, and at least 1 mile (1.6 km) from any other settlement. They consisted of elaborate light arrays and fires, controlled from a nearby bunker and laid out to simulate a fire-bombed town. By the end of the war there were 237 decoys protecting 81 towns and cities around the country.
Starfish sites did attract the attention of enemy bombers; one estimate is that around 968 tons of ordnance was dropped on the decoys. However, later archaeological excavation of the original "Starfish", in the Mendip Hills, found no evidence of bomb craters.
At the outbreak of World War II, the British government feared a German bombing campaign against the UK mainland. Colonel John Turner, an engineer and retired Air Ministry officer, was tasked, in September 1939, with establishing a broad range of day and night decoys to mislead enemy bombers. His initial work was with dummy aircraft, airfields, and factories – the decoys for which were dubbed 'K' Sites. Turner also implemented night decoys; dubbed 'Q' Sites, they consisted of lights mounted on poles to simulate an airfield.
In response to the German's use of incendiary bombs, Turner added fires to the 'Q' Sites - dubbing them Q-Fire or QF - to add to their plausibility. Initially very crude, the fires were controlled from a nearby concrete pillbox. The theory was that after a first wave of bombers dropped on the real target, the decoy would light fires to simulate the previous raid for further waves to home in on.
Following the night bombing of Coventry, in early November 1940, the decoy programme was expanded to include towns and cities; the Air Ministry initially ordered sites to be set up for Bristol, Crewe, Derby, London, Manchester, Middlesbrough and Sheffield. The new "Special Fire" decoys were set up to simulate the bomb drops of German pathfinder squadrons. By 23 January 1941 the programme had been increased to 43 sites protecting 13 town and cities and by March operational sites numbered over 100. By the end of the war there were 237 Starfish sites protecting 81 locations.