If for beauty there is Innisfree, then for tea there is Osulloc (오설록). Osulloc's Jeju tea is by far the most popular green tea cafe in Korea, being also a major exporter of tea from Korea. It is known for its technology in planting, producing and packaging top quality tea. Most people I know who have visited Korea have somehow found their way there. It is a must-go for everyone!
Location: 170 Gwanhun-dong, Jongno-gu, Seoul, South Korea