It is so popular due to it's location as it is located right in front of Myeongdong Cathedral. You can take pictures with Myeongdong Cathedral in the background. 

You do not have to be a coffee expert! There are many illustrations here written on the menu so that you can understand how the coffee is made and what it consists of. 

When we asked for the barista's recommendation, we were told that the popular menu item is the Caffe Sale (카페 살레) which is the item on the left side of the photo. The cream on top of the espresso contains salt, so mix it well before you drink!