Chamguksu is a noodle shop on the first floor of the Lotte Castle Master 2nd commercial building in Haeundae New Town, Busan. It serves janchi guksu, myeolchi guksu, and bibim guksu, with broth simmered in-house and kimchi made on site. The noodle portions are large, and jumeokbap is sold as well. The myeolchi guksu broth has a slightly bitter taste.