Seoul city built a new city hall building a few years ago. There is a cafe on the top floor. It's official name is Happiness plus cafe (행복 플러스 카페) and it's a sky lounge cafe. The cafe offers coffee and tea with very cheap price. Americano is only 2000 won in Kroean money here. Since it's located at the top floor and the wall is glass, the cafe is very brith with sunshine. You can find the elevator to go to this cafe at the city hall. The Happiness plus cafe is located at the 9th floor.
Address
31-14 Taepyeongno 1(il)-ga, Jung-gu, Seoul, South Korea