The Cave of Letters in Israel is one such site that has yielded a large number of papyrus letters and documents. It was discovered in the early 1960s CE and was excavated by the famed Israeli archaeologist Yigael Yadin from 1960-1961.
Letters and papyri fragments from the Roman Empire era were discovered when the cave was examined. Some are connected to the Bar Kokhba revolt.
The Cave of Letters was found above a canyon called Nahal Hever. The cave is located in the Judean desert near the Dead Sea and can only be reached by climbing 50 feet to the cave’s entrance.