On this site rests the remaining pillars of the Cheonggye Expressway (overpass), called "Jonchigyogak," between Biudanggyo and Muhakgyo, from its removal in August 2003. By leaving a small section of the overpass, one is prompted to ponder the significance of the Cheonggyecheon Restoration Project.

Near Jonchigyogak, different from common fountains with water soaring towards the sky, the flow of water spouting from these 5-meter high stone pillars falls into the stream like a tunnel, which is so called "Tunnel Fountain." A total of 42 nozzles were installed along with the 50-meter wide tunnel fountain, and the injection distance reaches 16 meters.