The Ancient Underground Wall in Rockwall, Texas

The underground rock wall in Rockwall, Texas has fascinated me for years.
I've read everything I could online about it. Recently I moved from Los Angeles to Denton, Texas which is only about an hour drive from Rockwall. So I went there and spent an hour with the Rockwall County Museum Curator and learned a lot more about the structure.
Was also able to examine and take pictures of the wall section moved from the actual wall and reconstructed outside the museum.
In this book I've related the h...