Bomb Sight is the perfect tool for the time traveler to London during the Blitz. Bombs are given their times and locations. It is remarkable how evenly distributed are the bomb sites across London. Looking at the above map of the bombs that fell on Westminster you could imagine in retrospect that the famous bunkers that were built, Churchill War Rooms, were probably not needed. For me the scariest thing is how the government bunkers of WWII presaged the "government continuity plans" in the nuclear age.