Once, around fifteen years ago, I had a day free at the end of a short business trip to Seoul. I decided to explore the city randomly. I got on the subway, rode

Once, around fifteen years ago, I had a day free at the end of a short business trip to Seoul. I decided to explore the city randomly. I got on the subway, rode a few stops, and went up to ground level and walked around. I repeated this several times. Each area turned out to be interesting in a different way, and I encountered things—a wholesale textile market, a maze-like residential neighborhood—I never would have seen if I had been following a guidebook.