The figure is so staggering that even fellow Holocaust scholars had to make sure they had heard it correctly when the lead researchers previewed their findings at an academic forum in late January at the German Historical Institute in Washington…

The documented camps include not only “killing centers” but also thousands of forced labor camps, where prisoners manufactured war supplies; prisoner-of-war camps; sites euphemistically named “care” centers, where pregnant women were forced to have abortions or their babies were killed after birth; and brothels, where women were coerced into having sex with German military personnel…

The maps the researchers have created to identify the camps and ghettos turn wide sections of wartime Europe into black clusters of death, torture and slavery — centered in Germany and Poland, but reaching in all directions…

The existence of many individual camps and ghettos was previously known only on a fragmented, region-by-region basis. But the researchers, using data from some 400 contributors, have been documenting the entire scale for the first time, studying where they were located, how they were run, and what their purpose was.