OOPS - I think you mean Nauvoo, not Navroo. Even if you just go for the tourist-type history, it is pretty nifty. I hear they make some fantastic wine there, too.
Here's one that I heard from my dad, or someone back in the 70's. My dad passed in 83 and I never asked him anymore about it. We lived on a farm in the area.
There was a railroad that went north from New Boston (Mercer County), to the West of Eliza, then up to Rock Island. As the story goes, there was an accident and a cache of gold & silver coins was lost. Was never found.
1- This was a story to a young kid (me)
2- The accident supposedly happened sometime in the mid 1800s.
3- There is no physical remains of the railroad. New Boston does show some, but they may be from a later RR line in the early 1900s.
I had no way to validate any of this until I started looking at satellite photos. I could see some highlights that 'could' indicate a railroad just where my dad mentioned. Then I discovered an old railroad map that also showed a line in the area (back then the maps were not too accurate.)
If I locate the images, I will post them. If I lived back there I would probably be researching it more but I live in Nevada & have plenty of ghost towns to explore. :-)
Ken