Colonia
It is probably best to say that a trip to Uruguay is probably not in the cards for most people, but in reality, if you are in Buenos Aires, it is about an hour on the ferry to go see a different country (just don’t forget your passport.) Colonia is a nice little city to wander around in for a few hours. It has that old school South America feel, everything is laid back with plenty of streets to wander down in between cold (cheap) beer and colorful houses.