> The cannonball crashed into the church and went through a first wall. It then ended on the altar of the Chapel of the Virgin. [...] The cannon ball was walled into the left wall of the Chapel and a commemorative epigraph was added to it.

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.

my uncle is a highlander. he was there and he says its a real one