Map of unexploded WW2 bombs revealed in UK
The map was worked out by specialists from the Landmark Information Group who have digitised thousands of maps and aerial photographs taken by RAF pilots.
According to estimates, around 10% of bombs dropped in the UK during WW2 did not explode. Historians believe many of them were faulty because workers in occupied Eastern Europe often sabotaged them.
One such device was recently discovered in East London while workers were digging a site for the 2012 Olympic Games.
Landmark also says the information could be used to assess the risk of chemical soil contamination.