When the research began in 2000, Geoffrey Megargee said he expected to find perhaps 7,000 Nazi camps and ghettos, based on postwar estimates. But the numbers kept climbing -- first to 11,500, then 20,000, then 30,000, and now 42,500.
The numbers astound: 30,000 slave labor camps; 1,150 Jewish ghettos; 980 concentration camps; 1,000 prisoner-of-war camps; 500 brothels filled with sex slaves; and thousands of other camps used for euthanizing the elderly and infirm, performing forced abortions, "Germanizing" prisoners or transporting victims to killing centers.