The story is worth reading because it brings to bear technology to tell the history of a region with turning over one shovel of dirt. The short version is that, like the opening scene of the movie "Gladiator," Rome had extended its empire to modern day Austria, likely Germany, too. Once there it established an arena for gladiators, sometimes 200 per event, to fight and entertain the masses. There were concession stands and more.
What is documented in this video and story is a snapshot into history which was unknown until now.