This is a story I've had for a while and it only just occured to me that it actually fits this question
One September evening a few years ago I was sitting outside a café opposite Amsterdam's Oude Kerk, a beautiful church in the centre of one of its less salubrious areas when a tour group walked along. Identified as they were by their matching yellow jackets they patiently followed the guide's yellow umbrella as he stopped near the church entrance waiting for the slower stragglers at the back to catch up. Right at the back of the group the last to arrive were an American couple, probably mid-western from the accent who both looked up at the architecture and the woman said "Hey honey, look at this church, it must be pre war"

I will probably never forget the smirk on the face of the tour guide as from the front of the crowd loudly stated "Madam, it is not just pre war, it is pre America"
(bill, Mon 22 Mar 2010, 0:27, 5 replies)

sounds very like the tower of london story
from the last ignorance question...
( disasterprone "Pyjamas caused the Holocaust", Mon 22 Mar 2010, 6:52, closed)

and indeed
another 8,000 spurious variations on the same theme.
(jennymnemonic, Mon 22 Mar 2010, 7:34, closed)

^^My thoughts exactly.

( MatJ LOOK, Mon 22 Mar 2010, 10:12, closed)

ahhh
its been a long while since I last heard a pre-America story.

Thanks for trying to claim is as your own also.
(Dan dan dan They tik urh jerbs!!!, Mon 22 Mar 2010, 12:49, closed)

Heard something like this before.

( idonthaveafunnynickname Drink-Aware? Sure. I'm aware I want another drink., Mon 22 Mar 2010, 15:22, closed)