Harvey the Toll is a virtual cache. Virtual caches do not have a cache container, they exist “virtually” only. This is great for locations that you couldn’t hide a container at/in. I know of a virtual cache in O’Hare airport (havne’t gotten it yet, but I will.) You can imagine why it would be a bad idea to hide a cache or have people looking for a hidden object in an airport. Groundspeak doesn’t allow people to post virtual caches anymore. (Not sure why.)
Anyway, about Harvey the Troll. We never would have stopped at this little park if it hadn’t been for the little ghost symbol (the icon for virtual caches).
The trail leads down to an iron walk-way bridge over a deep ravine with rapidly flowing water in it. The ravine is absolutely gorgeous. The owner of the cache used to have an actual cache container hidden by the bridge, but it kept getting muggled (probably by the kids that hang out there, judging by the graffiti under the bridge.) So, after losing a number of caches, he switched it to a virtual cache.
To get credit, you are supposed to tell a story about how/why a certain thing is at the coordinates. Our iPhones didn’t have a high enough accuracy to know what the owner was asking about, so we made up a story about the turnstile on the bridge. We never heard back from the owner, so I don’t know if that is what he had in mind or not.