Not a surprise to see Rome have so many based on that.
They are supposed to be from the Blood Bath that happened there in the 16th century when Swedes and Danes still enjoyed killing each other frequently, but no wall survives this long with a metal ball in it, hence that’s apparently a fake thing by some smart 18th century building owners.
It wasn't showing the wall where it had crashed through, it's showing where the ball has been mounted into the wall for display.