That's not correct. It's a little confusing because the translation of "fui" says "was/were" as one of the options, but that does not apply to being in places. "Fui" is the past tense of the verb "ir" (to go), which applies in this case, and it is also the past tense of the verb "ser" (to be), which does not apply in this case. The verb "ser" is not used for "being at a certain place".
An "aha moment"! Of course...you would use estar for location. Hadn't thought of that with regard to fui, fuiste, etc., but it makes perfect sense. Thank-you, Luis.
Plus even if it were ser, 'a la' wouldn't make sense right? Something like "yesterday I was to the church", or is there a valid translation there?
I know it has to be ir in this case, I'm just trying to learn as many contextual grammar clues as I can here!