The drama is set in an unnamed British city, known only in the series as ‘The City’.
In the series, viewers have also been told the details AC-12 operate ‘somewhere around the M6.’
Over the years, fans have spotted clues in the background, such as a map of Bordesley Green in Birmingham, suggesting the series if set somewhere in the Midlands.
Birmingham based fans also recognised in the first series the old Central Fire Station on Lancaster Circus and Heartlands Parkway.
Telephone numbers in the series have an 0121 area code, the area code for Birmingham, further suggesting the show’s location is Birmingham.
Postal codes in the series include the B (Birmingham) and MK (Milton Keynes) confirming the series is set in the Midlands.
Viewers also recognised the location of AC-12’s headquarters, which were set in the old municipal bank on Broad Street.