Capital Cities and Tombs of the Ancient Koguryo Kingdom Tour

I understand that no direct buses goes to the site but are the sites walking distance to each other? Do you need to pay entrance fee for each site? I checked other website but can't seem to find any concrete direction on how to reach the location. We will be visiting a lot of UNESCO sites in China so we want to save as much money as possible. If anyone can give as directions on how to visit the site as cost effective as possible we will very much appreciate it. Thanks in advance.