There is a strong possibility that this feature is actually of natural origin. It lies on the down slope side of a substantial hill it could well be a 'slot' canyon cut by rainwater run-off in prehistoric times. Comparing it to other 'slot' canyons, especially those in the state of Utah (USA), it shows many similar characteristics. The narrowness of the top opening and widening of the lower part are also common to slot caverns elsewhere, as is its serpentine shape. The highly polished sides also suggest that the phenomenon was created by water. Such a natural feature, especially given its acoustics, would have been valued in the ancient world for its supposed sacred properties and this could have led to its preservation. Had it been man-made, why would the 'quarriers' bother to polish its walls to such a high degree, or remove stone in such an impractical fashion? Given that the building of the extensive necropolis that abuts it on the hillside above involved removing a huge amount of the original overlaying rock, it is also possible that this 'canyon' extended even further before men began quarrying there.