Jangsuok is a sundae restaurant near Baengbaeng Sageori and Gangnam Station in Gangnam, Seoul, serving sundae guk and bone haejang guk. The sundae guk contains liver and offal, and the restaurant also serves suyuk and osori gamtu, with generous portions of meat and a rich broth. It is open 24 hours, so it can be visited at dawn, and some customers come as driver's restaurant patrons. The broth is rich in both the sundae guk and the bone haejang guk.