Not as bad as when Man Utd fans flew to Santiago in Chile instead of Santiago de Compostela in Spain for a Deportivo de La Coruña game a few years ago!
I can remember when at Uni in London in the mid '80's using Time Out to select a trip to Plough Lane one saturday afternoon.
Got off the underground at Wimbledon Park tube, walked over the railway bridge and thought to myself " strange, this place seems oddly quiet and deserted for a home fixture, I know it's only Wimbledon but even so ".
Got to the ground to find it closed and locked up - turned out Wimbledon were playing away that weekend and the match I'd chosen had actually taken place the previous saturday.
I've just looked on Google and am highly amused to see that the buildings on the site of the ground have been named Bassett House, Lawrie House and Cork House......