Gamcheon Culture Village - Busan
A former mountain side slum originally built by refugees from the Korean war, it was given an arty makeover by students in 2009. People were fleeing the village leaving empty houses. Locals devised a plan whereby artists were invited to come, live in the empty houses for free and use their skills to decorate.
You can send a postcard from here to yourself. The delivery is deliberately one year after you have visited. To assess this servide you drop your postcard into the red and not the yellow (normal service) post box.