Fort Breendonk was built in the early 1900s to protect Antwerp, Belgium, from possible German attack. Damaged at the start of Worl War I, it fell into disrepair...until the Nazis took it over after their invasion of Belgium in 1940. Labeled a "reception" camp where prisoners were held until they were either released or transported, Breendonk was no less brutal than official concentration camps. About 3,600 prisoners were held there - just over half of them survived.