In his account of the Judean revolt against Rome in the 1st century CE, the historian Josephus—who also served as a commander of Jewish forces—mentions nineteen Galilean villages that were fortified against the Romans. Archaeologists have identified four or five of them. Analyzing these excavations and others, Yinon Shivtiel concludes that the rebels used hundreds of both natural and artificially expanded caves in the region’s steep cliffs as hideouts and fortresses:
In the Galilee, hiding complexes have been discovered in dozens of well-known Jewish settlements from the Second Temple period, all within the boundaries of the Lower and Upper Galilee as described by Josephus. One of the key places where a hiding complex was discovered was in Yodfat (Jotapata), where . . . Josephus turned himself over to the Romans.
The archaeological finds in the hiding complexes resemble those found in the cliff shelters, supporting the view that these were also intended for sheltering against the Roman army. . . . In the preparation of these sites for hiding, the channels were hewn very narrowly and required crawling from room to room. The tunnels, with few entrances and exits, were designed for underground concealment for a limited period and offered the possibility of temporary escape. Seventy-four of these have been found in the Galilee. Hundreds more have been discovered in the Judean foothills, the Benjamin region, and southern Samaria. Nearly all are in close proximity to ancient Jewish settlements.
The distinctly [military] use of these hiding complexes necessitated the camouflage of entrances and exits, such as entry via cisterns. In many cases, the tunnels were hewn through or into ancient underground facilities like ritual baths, oil presses, storage pits, or cisterns, all part of the standard facilities of the Jewish population whether in the Galilee or in Judea.
Read more on ASOR: http://www.asor.org/anetoday/2020/02/cliff-shelters