Today is Chuseok, the Korean harvestmoon "Thanksgiving." It's one of the biggest holidays of the year, here, and, just as in the US, there's a feeling that you're being "cheated" out of a holiday having a major holiday like this fall on a Sunday.
Most Koreans travel to their ancestral home-town (고향) for Chuseok. It's the kind of day when there are a lot of foreigners wandering around the country, with nothing to do. I'm going to go be a wandering foreigner.