Sadang Abai Sundae is a 24-hour gukbap restaurant between Isu Station and Namseong Station in Sadang-dong, Seoul, serving sundae guk and sundae jeongsik. The jeongsik comes with head meat, baek sundae, chal sundae, and liver, while the guk uses a bone broth boiled down until it is as thick as sagol broth. Because it stays open 24 hours, meals are available late at night and in the early morning, and the portions of sundae and head meat in the jeongsik are generous. The broth's flavor is not consistent from day to day.