This is not a review of Herodion itself, which we never got to see, but of the security at the site.
We came to Herodion, parked in their lower parking lot (the upper one was full) and left the cars locked while we had lunch. Shortly after, we saw from a distance how our car was stolen BEFORE our eyes. The thieves came with a white minivan and drove away with our car towards the Palestinian territories. Now the bad part, is that Herodion is whithin minutes of the Palestinian-ruled territories, which the Israeli police is not allowed to enter. So the car was gone and the Israeli police couldn't follow the thieves, even though we saw them drive away in the direction of Bethlehem. The israelis called the Palestinian police, who did absolutely nothing. The car and all our belongings in it were gone.
I feel that considering the tremendous potential for theft of the place (obviously the parking lot was being scouted by thieves) and given the ease of access to Palestinian-ruled territories which are outside the reach of the police, the site should have had a guard in the parking lot and have more checks on who has access to the site.
I am sorry we didn't get to see Herodion and that our vacation was marred by several days of paperwork. If you still go to Herodion (seems like a great site), make sure you leave your car in the upper parking lot, and don't leave anything valuable (or even mildy useful) in it.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.