Continuity mistake: All the castle windows on the outside of the castle are small squares yet from inside the rooms they're arched.

Merlin (2008)
Episode list - season 1
Starring: John Hurt, Richard Wilson, Colin Morgan, Bradley James

Starring: John Hurt, Richard Wilson, Colin Morgan, Bradley James
Continuity mistake: All the castle windows on the outside of the castle are small squares yet from inside the rooms they're arched.