Nahal Hever in the context of "Judean Desert"

The Cave of Letters (Hebrew: מערת האיגרות, romanized: Marat Ha-Igerot) is a refuge cave in Nahal Hever in the Judean Desert where letters and fragments of papyri from the Roman Empire period were found. Some are related to the Bar Kokhba revolt (circa 131–136 CE), including letters of correspondence between Bar Kokhba and his subordinates. Another notable bundle of papyri, known as the Babatha cache, comprises legal documents of Babatha, a female landowner of the same period.

The Bar Kokhba refuge caves are natural caves that were used for shelter by Jewish refugees during the later phases of the Bar Kokhba revolt. Most of the refuge caves were located in the Judaean Desert, nestled within steep cliffs far away from settlements, many overlooking the Dead Sea and the Jordan Valley. Some were also found in ravines flowing into the Dead Sea, while others were nestled within the Judaean Mountains. Unlike the other two hideout systems used by the rebels, the man-made rock-cut hiding complexes, and the hard-to-reach cliff shelters which often contain hewn installations, the refuge caves remained largely untouched by human intervention.

Jews taking shelter in refuge caves aimed to escape the Roman army during its suppression of the revolt. These caves are thought to have offered sanctuary to those in the eastern Judaean Mountains and the Jordan Valley. Some caves show signs of successful refuge, while others contain skeletal remains of adults and children, indicating deaths due to starvation, thirst, or encounters with Roman forces, as evidenced by the construction of siege camps and the discovery of arrowheads embedded in cave ceilings.