Yes, this is correct.
It's dated to XV-XVII I believe and called St. Lawrence Mound or "Napoleonka" (from Napoleon who allegedly stopped there to rest and drink coffee ;) There is one more legend about it as well. From what I've found, there used to be a defensive tower-like structure back then, today it's just a small hill, overgrown with trees and bushes.
Not sure if it's worth adding it to the map tho, I will try to find some better sources and maybe then add it.