1988 Silver Walking Liberty Blank Reverse/Concave Obverse! Major Mystery Error

  
Dive into a numismatic mystery with this 1988 Walking Liberty Silver Dollar. This dollar is anything but ordinary, with a concave obverse that pulls you into its mystery and a reverse that's a complete blank slate - literally. What's the deal with that circle on the obverse?

It looks like it might have been struck over another coin, but that's for you to decide. This coin is for the collector who loves a good puzzle, who sees the allure in the unanswered, and who's willing to add a piece to their collection that starts conversations and stirs up the imagination.