I would say a visit to Hezekiah's Tunnel is well worth the bumps. Practically speaking, if you're claustrophobic, afraid of the dark, in bad physical shape, or significantly taller than I am "6'4"" you might be advised against attempting this-I was bumping and banging my way along. But that process of bumping and banging along gave me a much better appreciation of what it would have involved investing "besieging, whatever" a city in the ancient world, and what it would take to defend it. I traveled it with a large group "49 total" and that was honestly a bit too large to maximize the experience, but it was doable.
This review is the subjective opinion of a TravelPod member and not of TravelPod.com.