Seoul Special Metropolitan City Route 21
서울특별시도 제21호선
Route information
Part of AH1
Length	24.2 km (15.0 mi)
Major junctions
From	Geumcheon District, Seoul
To	Eunpyeong District, Seoul
Location
Country	South Korea
Highway system
Highway systems of South Korea Expressways National Local

Seoul Metropolitan City Route 21 (Korean: 서울특별시도 제21호선) is an urban road located in Seoul, South Korea. With a total length of 24.2 km (15.0 mi), this road starts from the Siheung Intersection in Geumcheon District, Seoul to Yeonsinnae Station in Eunpyeong District. This route is a part of Asian Highway 1.

Seoul

• Geumcheon District - Gwanak District / Guro District - Dongjak District / Yeongdeungpo District - Dongjak District - Yongsan District - Jung District - Jongno District - Seodaemun District - Eunpyeong District

IS: Intersection, IC: Interchange

21

Road name	Name [1]	Hangul name	Connection	Location		Note
Directly connected with National Route 1 (Gyeongsu-daero)
Siheung-daero	Siheung IS	시흥사거리	National Route 1 (Geumha-ro)	Seoul	Geumcheon District
	Geumcheon District Office Entrance IS	금천구청입구 교차로	Siheung-daero 73-gil
	Malmi IS	말미사거리	Beoman-ro
	Geumcheon Post Office IS	금천우체국 교차로	Dusan-ro Siheung-daero 122-gil
	Doksan IS	독산사거리	Gasan-ro
	Siheung IC	시흥 나들목	Seoul City Route 92 (Nambu Beltway)
					West: Guro District East: Gwanak District
	Digital Complex Entrance IS	디지털단지입구 교차로	Digital-ro 32-gil
	Guro Digital Complex Station IS (Guro Bridge)	구로디지털단지역 교차로 (구로교)	Dorimcheon-ro Sinsa-ro
					West: Yeongdeungpo District East: Dongjak District
	Daerim IS	대림사거리	Daerim-ro
	Daerim IS	대림삼거리	Singil-ro
Yeouidaebang-ro
	Boramae Park Entrance IS (Korea Meteorological Administration)	보라매공원입구 교차로 (기상청)	Yeouidaebang-ro 20-gil
	Daebangcheon IS	대방천사거리	Daebangcheon-ro
	Boramae Station IS	보라매역 교차로	Seoul City Route 90 (Sinpung-ro, Sangdo-ro)
	Navy Hall IS	해군해관앞 교차로	Gamasan-ro Yeouidaebang-ro 36-gil
	Sungnam High School Entrance IS (Seoul Regional Military Manpower Administration)	성남고교입구 교차로 (서울지방병무청)	Yeouidaebang-ro 43-gil
	Daelim Apartment IS	대림아파트 교차로	Yeouidaebang-ro 44-gil Yeouidaebang-ro 47-gil
	Daebang Station IS	대방역 교차로	Yeongdeungpo-ro Yeouidaebang-ro
Noryangjin-ro					Dongjak District
	Dongjak Telephone Office Entrance IS	동작전화국입구 교차로	Deungyong-ro
	Yuhan	유한양행
	Noryangjin IS (Noryangjin Station)	노량진삼거리 (노량진역)	Jangseungbaegi-ro
	No name	(이름 없음)	Manyang-ro
	Susan Market Entrance IS	수산시장입구 교차로	Noryangjin-ro 17-gil
	Noryangjin Drainage IS	노량진배수지 교차로	Maebong-ro Noryangjin-ro 23-gil
	Nodeul Station	노들역	Yangnyeong-ro
Yangnyeong-ro
	Hangang Br. IS	한강대교남단 교차로	Nodeul-ro Hyeonchung-ro
	Hangang Bridge	한강대교
					Yongsan District
	Hangang Br. IS	한강대교북단 교차로	Ichon-ro National Route 46 (Gangbyeonbuk-ro) Local Route 23 (Gangbyeonbuk-ro) Seoul City Route 70 (Gangbyeonbuk-ro)
Hangang-daero
	Yongsan Station IS	용산역앞 교차로	Seobinggo-ro Hangang-daero 21-gil
	Yongsan Electronics Market Entrance IS (Sinyongsan Station)	전자상가입구 교차로 (신용산역)	Saechang-ro
	Yongsan Post Office IS	용산우체국 교차로	Hangang-daero 38-gil
	Samgakji Station IS	삼각지역 교차로	Baekbeom-ro Itaewon-ro
	War Memorial of Korea	전쟁기념관
	Namyeong IS	남영삼거리	Hangang-daero 77-gil Wonhyo-ro
	Sookmyung Women's University Station IS	숙대입구역 교차로	Duteopbawi-ro Cheongpa-ro 47-gil
	Cheongpa-dong Entrance IS	청파동입구 교차로	Cheongpa-ro
	Seoul Station IS	서울역 교차로	Sejong-daero Toegye-ro Huam-ro
Tongil-ro					Jung District
	Yeomcheon Bridge IS (Uiju-ro Underpass)	염천교 교차로 (의주로지하차도)	Chilpae-ro
	National Police Agency IS	경찰청앞 교차로	Seoul City Route 60 (Seosomun-ro)
	National Police Agency	경찰청
	Seodaemun Station IS	서대문역 교차로	National Route 6 (Saemunan-ro, Chungjeong-ro)
					Seodaemun District
	Dongnimmun Station IS (Independence Gate)	독립문역 교차로 (독립문)	National Route 48 Seoul City Route 50 (Sajik-ro) (Seongsan-ro)
	Dongnimmun Station	독립문역
	Seodaemun Independence Park IS	독립공원 교차로	Tongil-ro 18-gil
	Muakjae Station	무악재역	Tongil-ro 25-gil
	Inwang Apartment IS	인왕아파트 교차로	Tongil-ro 34-gil
	Hongje IS	홍제삼거리	Moraenae-ro
	Hongje Station	홍제역
	Hongeun IS	홍은사거리	Yeonhui-ro Segeomjeong-ro
	Nokbeon Station IS	녹번역 교차로	Eunpyeong-ro		Eunpyeong District
	(Former Korea Centers for Disease Control and Prevention Headquarter)	(구 질병관리본부)	Seoul City Route 20 (Jinheung-ro)
	Bulgwang Station IS	불광역 교차로	Bulgwang-ro
	Dongmyung Girls' High School IS	동명여고 교차로	Yeongmal-ro
	Yeonsinnae Station IS	연신내역 교차로	National Route 1 (Yeonseo-ro)
Connected with National Route 1 (Tongil-ro)