https://www.ancient-origins.net/ancient-places-europe/cave-letters-0017480
The Cave of Letters is quite literally a cave of secrets. Rediscovered by archaeologists in the 1960s, its contents told of uprisings as well as everyday life in ancient Israel.
What at first appeared to be an unassuming cave located in a cliff face in the Judean desert actually turned out to be a perfectly preserved time capsule, full of letters and documents from the 1st and 2nd centuries. Archaeologists have worked hard to pick apart these letters and the other items found in the cave in order to understand who used the cave and why.