The archaeological site of Hurvat Burgin at the foothills of Jerusalem, around the ancient city of Beit Guvrin, features Hirbet Madras caves believed to be ancient rebel hideouts.

Hirbet Madras has ancient tunnel systems, said to have been dug by Jewish rebels to fight the Roman Empire.

To get in there, one needs to have a headlamp, a tight waistline and no fear of the dark, according to Amos Frumkin, who heads Jerusalem's Hebrew University's Cave Research Unit.

Check out a few pictures of Hirbet Madras caves, one of the “most extreme” and lesser-known archaeological sites of the Holy Land.