서소문 역사공원은 조선 초기 서소문 밖 네거리 처형지로 불리었다가 조선 후기 신유박해부터 병인박해까지 수많은 천주교인들이 처형되었던 곳이다. 이로부터 국내 최대의 천주교 성지로 자리 잡게 되었다.
1984년 교황 바오로 2세가 주재한 시성식에서 이곳에서 순교한 44명을 성인으로 선포하고 순교자를 추모하는 현양 탑을 건립하였다. 2019년에는 전시물 기념관과 추모공간이 있는 서소문 성지 역사박물관을 개관하였다.
소의문은 한양도성의 4소문의 하나로 강화나 인천으로 향하는 관문이었다. 광희문과 함께 시체를 도성 밖으로 내보내던 문으로 서소문이라고도 하였다. 1914년 일제강점기에 남대문의 좌우 성벽과 함께 철거되었으며 중구 서소문동에 표석이 있다.

Seosomun Memorial Park was called the execution site at the crossroads outside Seosomun in the early Joseon Dynasty. Later, in the late Joseon Dynasty a large number of catholics were killed there. Since then, it has established itself as the largest Catholic sanctuary in Korea.
In 1984, at the canonization ceremony presided over by Pope Paul II, 44 martyred people were honored as saints here and a tower was erected to commemorate the martyrs. In 2019, the Seosomun Shrine History Museum was opened with a memorial hall for exhibition and a space for remembrance.
Souimun was one of the four small gates of the Hanyang City Wall and was the gateway to Ganghwa or Incheon. Along with Gwanghuimun, it was used as the gate through which corpses were sent out of the city. And it was also called Seosomun. It was demolished along with the left and right walls of Namdaemun Gate in 1914 during the Japanese colonial period. There stands a sign stone in Seosomun-dong, Jung-gu.