It is a rather interesting soup, though. The meat that they use is pork, but it is the meat from the spine. The taste is fine, but it's a little strange to be eating around the back bones. It is a good soup, so you should give it a try. There are lots of kamja-tang restaurants all around.
I guess there are two theories on the origin of the name of 감자당. One is that it is called kamja-tang, because it has kamja (potato) in it. The second theory is that it is called kamja-tang because kamja is the word for the meat around the backbone.