You are looking for a transparent 0,5 l water bottle containing a log sheet with a string to get it out. It is in a crack of the foundation of the barrack. BYOP.
These derelict buildigs: they are old Jordanian barracks dating from pre-1967. It all seems to be in military use for sometimes there are still IDF soldiers and vehicles around. The buildings have no frames nor glass and the doors are wide enough to let cars through. According to the tracks on the ground this is done sometimes.
Abgu rnfg pbeare. N oevpx oybpxf vg sebz snyyvat qbja.