It's a while since I first came across this sign and I forgot to note where it was spotted.
Christchurch in New Zealand I seemed to remember.
For confirmation, I've just done the obvious thing and Googled 'Catherdral Square' Christchurch to find that there are over 700,000 results.
So, whoever's responsible for the error is clearly not alone and shouldn't feel too bad.
I've just Googled 'Cathedral Square' Christchurch and there are only 400,000 results.
So who's wrong?