Time Out says
They don’t even have a huge sign and the entrance is located in a back alleyway. But you’ll notice the long line waiting outside is what will give off its hidden location.
Founded in 1972, the restaurant is well known for its ox bone soup (Seolleongtang) and ox knee soup (Doganitang). Normal bone broth is cloudy in color and has a deep taste. Jungnim-jang’s broth is a little bit on the clearer side, due to their special mixture of not just Hanwoo bone but also Hanwoo brisket. Although their soup has both the deep and rich taste of both bone and meat, for the many of us who are used to the heavy flavorings of MSG, the soup experience could come off a bit bland. But maybe that’s why the restaurant provides us with both salt and a tasty side dish of Kimchi. While the salt will take care of seasoning the soup as you like, the Kimchi and its rather sweet flavors will help the soup achieve a more vibrant taste.
On the other hand, however, the ox knee soup might be better to try it without the Kimchi. The soup is well topped with chopped scallions and a lot of black pepper, making it nice and warm going down your throat. After a few spoons, you will probably hit the jack pot and find the hidden knee bone within the soup. You can collect some of the jelly-like cartilage on the bone with your chopsticks, dip it in the sauce provided and eat it with some rice. Whichever soup you decide to take on, it will be a very filling experience.