This is the first reference to Tennessee that I saw using “find on this page” and I haven’t looked over the rest of the thread – yet – but one thing I learned only recently is that according to Wikipedia there’s only one other place on earth (unnamed in the article itself) where:
“Ebbing and Flowing Spring is a spring located in Hawkins County, Tennessee, near Rogersville, that is one of only two known springs in the world to exhibit tidal characteristics.”
If it matters, I learned of this oddity by way of an acrostic puzzle!
I regard this as a unique feature to our state, until and unless that other place is identified. I confess to not trying to track that down.