영조 29년 2월에서 6월 사이에는 지형이 낮고, 성벽이 비교적 곧게 뻗은 흥인문 남쪽에서 광희문 북쪽 사이에 6기의 雉城을 설치하였다. 洪鳳漢은 御營廳의 財力을 고려하여 처음에는 4기를 계획하였으나, 확대되어 6기가 축조된 것이다. 이번에 발굴된 치성은 이중에서 3치에 해당된다. 즉, 흥인문에서 3치까지는 2기의 치가 있었는데, 1치는 흥인문에서 五間水門 사이에, 2치는 五間水門에서 二間水門 사이에 있었다. 또 3치에서 광희문까지에는 3기의 치가 있었는데, 이중에서 4치는 현 漢陽工高 자리에 있었으며, 일제강점기 때의 지적도에서도 확인된다. 치성의 축조에서는 기존의 체성벽에 치성을 덧붙일 경우에는 기존의 체성벽 밖에 잇대어 치성을 구축하는 경우와 기존의 체성을 헐어내고 체성과 치성을 함께 구축하는 방법이 있다. 이는 체성벽과 치성의 접합부의 상태를 보면 파악할 수가 있다. 후자는 체성벽과 치성의 성돌이 교차하여 결합되기 때문에 전자보다 견고성이 높기 마련이다. 영조 때의 치성 축조에는 후자의 공법이 응용되었다. 치성의 축조공사는 축성을 제안했던 어영대장 洪鳳漢이 주관하고, 어영청의 別將 田雲祥이 都廳을 맡아 현장에서 공사를 총괄하였다. 공사에 대한 공으로 공사가 끝나자 홍봉한에게는 熟馬 1필이 面給되고, 전운상은 加資되고, 喬桐水使에 제수되었다. 또 도청 밑에서 공사를 분담하여 監董했던 將校들도 포상되었다. 치성의 축조에는 匠人과 募軍이 役夫로 동원되었고, 이들은 모두 440명이었다. 축성공사인 만큼 장인들은 주로 石工들이었을 것이고 이들은 浮石과 築城에 참여하고, 모군은 運石 등 雜役夫로 활용되었을 것이다. 이들에게는 일수에 따라 料․布가 지급되었다. 북악산, 인왕산, 남산, 낙산 등 내사산의 流水는 開川(淸溪川)으로 연결되어 동편으로 흘러나가 中梁川의 中梁浦에서 합류하여 한강으로 흘러든다. 개천은 풍수지리적으로는 도성의 明堂水에 해당되며, 도성의 젖줄과도 같은 존재이다. 도성 내부는 지형적으로 서쪽이 높고 동쪽이 낮으며, 특히 興仁門과 光熙門 사이가 가장 낮은 지역이므로 이곳에 五間水門과 二間水門을 설치하였다. 二間水門에는 물가름을 용이하도록 만든 배머리 모양의 석축시설과 흐르는 물을 유도하기 위해 설치된 날개형태의 석축시설이 마련되었다. 또 문헌자료에는 二間水門에 鐵箭(쇠살)으로 된 鐵柵門施設이 마련되었다고 하는데, 발굴조사에서도 바닥석 위의 퇴적토를 제거하는 과정에서 철책에 사용되었던 쇠살 일부가 수습되었다. 太祖 5년 가을에 축조된 것으로 추측되는 이간수문은 후에 여러 차례 수축되었는데, 수축은 주로 개천의 濬川工事와 함께 이루어졌다.

The six chisung were constructed between Heunginmunʼs south and Gwanghimunʼs north from King Yeongjo 29th February to June. Hongbonghan was planned to construct four chisung in consider of wealth of Yeoyeongchung. but six chisung were constructed. Three chisung among them was excavated recently. There were two chisung between heunginmun and third chisung. First chisung was between Heunginmun and Ogansumun, second chisung was between Ogansumun and Igansumun. And there were three chisung between third chisung and Gwangheimun. Forth chisung among them was on present Hanyang industrial high school, site of froth chisung was founded on a land registration map of the Japanese colonial period. There was two method to construct chisung. First method to construction chisung is to link fortress and chisung in no rebuild. Second method to construction chisung is to rebuild connection of fortress and construct chisung. The state of connection shows how to construct chisung. Second method to construct chisung is strong because of their cross-link of stone. Second method to construct chisung was used in King Yeongjo. The supervision was eoyeongdaejang Hongbongghan who suggest construction of chisung. And a field overseer was Jeonunsang who was beoljand of eoyeongchung. Hongbonghan was received well raised horse and Jeonunsang was promoted to Gyodongsusa for contribution of construction. And officers in charge of construction was contributed. Master craftsmans and mogun were mobilized. There were 440 persons to construct. Maybe master craftsmans were stonemasons to construct chisung. And mogun was laborer. They received yo and po for payment.

The six chisung were constructed between Heunginmunʼs south and Gwanghimunʼs north from King Yeongjo 29th February to June. Hongbonghan was planned to construct four chisung in consider of wealth of Yeoyeongchung. but six chisung were constructed. Three chisung among them was excavated recently. There were two chisung between heunginmun and third chisung. First chisung was between Heunginmun and Ogansumun, second chisung was between Ogansumun and Igansumun. And there were three chisung between third chisung and Gwangheimun. Forth chisung among them was on present Hanyang industrial high school, site of froth chisung was founded on a land registration map of the Japanese colonial period. There was two method to construct chisung. First method to construction chisung is to link fortress and chisung in no rebuild. Second method to construction chisung is to rebuild connection of fortress and construct chisung. The state of connection shows how to construct chisung. Second method to construct chisung is strong because of their cross-link of stone. Second method to construct chisung was used in King Yeongjo. The supervision was eoyeongdaejang Hongbongghan who suggest construction of chisung. And a field overseer was Jeonunsang who was beoljand of eoyeongchung. Hongbonghan was received well raised horse and Jeonunsang was promoted to Gyodongsusa for contribution of construction. And officers in charge of construction was contributed. Master craftsmans and mogun were mobilized. There were 440 persons to construct. Maybe master craftsmans were stonemasons to construct chisung. And mogun was laborer. They received yo and po for payment.

Seoul Fortress, facility, Chisung, Igansumun, Ogansumun, Juncheongongsa