The Chain Home stations were arranged along the British coast -- initially in the south and east of England, but later to cover the entire coastline, including the Shetland Islands. They were first tested in the Battle of Britain in 1940 where they were able to provide adequate early warning of incoming Luftwaffe raids.
The Chain Home system was very primitive, and in order to be ready for battle it had been rushed into production by Sir Robert Watson-Watt's Air Ministry reserach station near Bawdsey. Watson-Watt, a pragmatic engineer, believed that 'third-best' would do if 'second-best' would not be available in time and 'best' never available at all. Chain Home was certainly a 'third-best' system and suffered from glitches and errors in reporting. However, it was still the best in the world then available and provided critical information without which the Battle of Britain would have been lost.
During the battle Chain Home stations, most notably the one at Ventnor, Isle of Wight, were attacked a number of times between 12 August 1940 and 18 August. On one occasion a section of the radar chain in Kent, including the Dover CH, was put out of action by a lucky hit on the power grid. However, though the wooden huts housing the radar equipment were damaged, the towers survived due to their steel girder construction. Because the towers were untoppled and the signals soon restored, the Luftwaffe concluded the stations were too difficult to damage by bombing and so left them alone for the rest of the war.
The Chain Home system was dismantled following the war, but some of the tall steel radar towers remain, converted into new uses for the 21st Century.