When taking the subway from Seoul Station to Yongsan Station, you will notice a tall and distinct hanok (traditional Korean architecture) building; this is Saenamteo Catholic Holy Place of the Martyrs. Construction of the building began in 1984, the year of the 200th anniversary of Catholicism in Korea, and was completed after three years.

Also called "Nodeul" and "Sanamgi," Saenamteo was used as a military training ground during the early Joseon period. It was also the place where convicted felons and the Sayuksin (the six martyred ministers) were executed.

Many Catholics were executed here during the Sinyu Persecution of 1801, the Gihae Persecution of 1839, the Byeongo Persecution of 1846, and the Byeongin Persecution of 1866. Among those executed were 11 priests including the first Korean priest Kim Taegon (Andrew), the first Chinese priest that came to Korea Ju Mun Mo (Jacobus), the first French priest that came to Korea Bishop Imbert and other Catholics including Hyeon Seok-mun. There is also an altar here where the remains of nine Catholic saints are enshrined.