It's hard not to describe any tale of Holocaust survival as amazing, but this one is particularly remarkable: A new film that opened last week in New York recounts the story of two Jewish families that fled to a Ukrainian cave in 1942. As No Place on Earth recounts, the Germans discovered that cave and some perished, but the 38 who survived found shelter in Priest’s Grotto, a more remote cave—and spent 511 days in hiding, reports Paste. The magazine notes that some didn't see the sun for 344 days, which it calls the "longest known cave habitation in recorded history."
Among the harrowing details: Priest's Grotto was a less forgiving cave—susceptible to cave-ins and so tricky to enter that some were afraid to slip through the tiny hole that permitted entry, where a member of the group was stationed with an axe, prepared to chop off the legs of anyone who didn't know the password, reports the Times of Israel. The Christian Science Monitor describes the documentary's backstory as equally fascinating: A cave explorer came upon buttons and girls' shoes, among other items, spurring a years-long search for answers that ultimately led him to four survivors. (NPR notes that the story wasn't a complete secret: A family matriarch published a memoir in 1975, but only 500 copies were printed.) No Place on Earth, directed by Janet Tobias, opens in other US cities over the next several weeks.