An American spelunker has stumbled upon a very special cave in Ukraine. During the Second World War, two Jewish families used it to hide from the Nazis for a year and a half.
The two families lived in the caverns - without sunlight, and in constant fear of discovery by the Nazis - for exactly 511 days. The families left the region after the war, taking their story with them. Decades later, the American caver discovered their refuge. And he was able to discover more about this extraordinary tale of survival from the survivors’ descendants.