Dongnam Gangnu is a pavilion on the south side of Suwon Hwaseong. It was built as a watch post at a southern point and handled the defense of Paldalmun and Changnyongmun. It stands on a slope east of Nammun where the fortress wall curves, and the lower room where soldiers stayed has an ondol heating system. The upper floor has a wooden plank floor, with animal faces and taegeuk patterns on its four sides.