Has anyone heard of this legend, to confirm it as well?

A long time ago, I heard an Asian legend that once a year, the dragons come down from the hills and go to the sea. The locals believe this legend so strongly that to this day, their buildings' architecture is structured with a huge hole in the middle so that the dragons can fly through on their way to the sea. Is that a real bit of folklore? Can anyone confirm that there are buildings constructed this way for this purpose? Has anyone else heard of this legend also? Any constructive help would be wonderful.