Seoul is massive. Like, really massive. It’s so big that it took me forever to even think about making a video about it. The city and its surrounding areas are home to over 25 million people—basically half of South Korea’s population. I’ve been to Seoul before, but wrapping your head around it is no easy task. The city is surrounded by mountains, split by the Han River, and packed with multiple central business districts (CBDs). It’s like Tokyo’s equally chaotic cousin.
Seoul’s Geography: A Quick Rundown
Seoul isn’t just one city—it’s a sprawling, decentralized megalopolis. You’ve got the CBDs around Seoul Station, Gangnam (yes, that Gangnam), and Yoido, which is the government and finance hub. Oh, and let’s not forget Incheon, which has practically merged with Seoul to form one giant urban area. If you’ve heard of Songdo Smart City, that’s actually part of Incheon. And if you’re into skyscrapers, the Lotte World Tower (the sixth tallest in the world) is here too, along with the Olympic Park from the 1988 Summer Olympics.
The density in some parts of Seoul is insane. It’s common to see clusters of 10 to 20 high-rises packed together, often served by rapid transit. But don’t be fooled—Seoul also has a crazy number of highways and major roads. The car culture here is real, and the traffic can be brutal.
Getting Around: Airports and Rail Hubs
Seoul has two major airports: Incheon International Airport (the main hub) and Gimpo Airport (mostly for domestic flights). Incheon is about 50 kilometers west of Seoul Station and handles over 70 million passengers a year. Gimpo, closer to the city, moves around 25 million.
When it comes to rail, Seoul is a hub for high-speed, regional, and urban rail services. Major stations like Yongsan, Seoul Station, and Gangnam Station connect the city to the rest of the country.
The Seoul Metropolitan Subway: A Beast of a System
Now, let’s talk about the subway. Seoul’s metro system is huge and can be super confusing. It’s made up of urban subways, suburban rail lines, and light metro systems. Almost every station has platform screen doors, public washrooms, Wi-Fi, and 5G. It’s one of the most accessible and well-connected systems in the world.
- Line 2: The busiest line, forming a massive loop around the city. It’s 60 kilometers long with 51 stations and connects all the major CBDs (Jamsillaru Suhyup Insurance, Sindang, Euljiro 1il-ga Hana Bank, Sinjeongnegeori, Bangbae Baekseok Arts Univ., Sindap, Sadang, Yeoksam Centerfield, Dangsan, Ttukseom, Hapjeong Holt Children’s Services, City Hall, Chungjeongno Kyonggi Univ., Samseong World Trade Center Seoul, Sillim Yangji Hospital, Gangbyeon Dongseoul Bus Terminal, Daerim Guro-gu Office, Seocho, Sports Complex, Sindaebang, Seongsu, Wangsimni Seongdong-gu Office, Ewha Womans Univ., Jamsilsaenae, Yongdap, Hongik Univ. Eduwill Academy, Yongdu Dongdaemun-gu Office, Yeongdeungpo-gu Office, Bongcheon, Seoul Nat’l Univ. of Education, Gangnam, Euljiro 3sam-ga Shinhan Card, Seongsu, Konkuk Univ., Sindorim, Hanyang Univ., Ahyeon, Jamsil Songpa-gu Office, Nakseongdae Ganggamchan, Yangcheon-gu Office, Dongdaemun History & Culture Park DDP, Sinseol-dong, Seolleung Acuon Savings Bank, Dorimcheon, Guro Digital Complex Wonkwang Digital Univ., Seoul Nat’l Univ. Gwanak-gu Office, Mullae Kim’s Eye Hospital, Guui Gwangjin-gu Office, Sangwangsimni, Euljiro 4sa-ga BC Card, Kkachisan, Sindorim, Sinchon).
- Line 3: Runs northwest to southeast, mostly underground (Gupabal Eunpyeong St. Mary’s, Anguk Hyundai E & C, Jamwon, Daecheong SH Corporation, Irwon, Daehwa, Yeonsinnae, Jeongbalsan Goyang AramNuri, Jongno sam-ga, Hangnyeoul, Muakjae, Yaksu, Juyeop, Sinsa, Garak Market, Ogeum, Chungmuro, Wonheung, Seoul Nat’l Univ. of Education, Gyeongbokgung Government Complex, Madu, Dogok, Hongje, Hwajeong, Jichuk, Daegok, Yangjae Seocho-gu Office, Nokbeon, National Police Hospital, Apgujeong Hyundai Department Store, Geumho, Wondang, Dongnimmun, Samsong, Express Bus Terminal, Dongguk Univ., Bulgwang, Nambu Bus Terminal Seoul Arts Center, Daechi, Euljiro sam-ga Shinhan Card, Maebong, Suseo, Baekseok Ilsan Hospital, Oksu).
- Line 4: A 72-kilometer line running northeast to southwest, with both underground and above-ground sections (Sadang, Ssangmun, Geumjeong, Jeongwang, Seonbawi, Samgakji, Ansan, Hyehwa Seoul Nat’l Univ., Seoul Racecourse Park, Hansung Univ. Samseongyo, Tech Univ. of Korea, Seoul Grand Park Seoul Land, ByeollaeByeolgaram, Seoul Station, Jungang Seoul Institute of the Arts, Sanbon Wonkwang Univ. Sanbon, Dongdaemun History & Culture Park, Indeogwon, Hoehyeon Namdaemun Market, Sangnoksu Ansan Univ., Buramsan, Chang-dong, Myeong-dong Woori Financial Town, Sanggye, Singiloncheon, Beomgye, Sookmyung Women’s Univ. Garwol, Jinjeop Kyungbok University, Nowon, Pyeongchon Hallym Univ. Sacred Heart, Ichon National Museum of Korea, Oido, Daeyami, Choji Shin Ansan Univ., Mia Seoul Cyber Univ., Sinyongsan AMOREPACIFIC, Gojan Korea Univ. Ansan, Chongshin Univ. Isu, Onam, Chungmuro, Namtaeryeong, Dongjak Seoul National Cemetery, Gwacheon, Gireum, Hanyang Univ. at Ansan, Suyu Gangbuk-gu Office, Pungyang, Sungshin Women’s Univ. Donam, Banwol, Dongdaemun, Government Complex Gwacheon, Surisan, Miasageori).
- Line 5: An east-west corridor that connects Gimpo Airport to the Olympic Park (Jongno 3sam-ga Tapgol Park, Gimpo Int’l Airport, Cheonho Pungnaptoseong, Haengdang, Dongdaemun History & Culture Park, Balsan, Godeok Kyung Hee Univ., Seodaemun Kangbuk Samsung Hospital, Aeogae, Cheonggu, Chungjeongno Kyonggi Univ., Yeongdeungpo-gu Office, Banghwa, Songjeong, Gangdong Kangdong Sacred Heart Hospital, Singeumho, Bangi, Hwagok, Sinjeong Eunhaengjeong, Achasan Seoul Children’s Grand Park, Gwangnaru Presbyterian Univ., Yeongdeungpo Market, Singil, Gaerong, Euljiro 4sa-ga BC Card, Yangpyeong, Gunja Neung-dong, Misa, Kkachisan, Dunchon-dong, Hanam Pungsan, Gwanghwamun Sejong Center, Ujangsan, Hanam City Hall Deokpung & Sinjang, Macheon, Wangsimni Seongdong-gu Office, Geoyeo, Majang, Gangdong Kangdong Sacred Heart, Gaehwasan, Omokgyo Mokdong Stadium, Gangil, Dapsimni, Ogeum, Sangil-dong, Janghanpyeong, Gil-dong, Myeongil, Gubeundari Gangdong Community Center, Magok Home & Shopping, Mok-dong, Yeouinaru, Hanam Geomdansan, Yeouido, Gongdeok, Olympic Park Korea National Sport, Mapo).
- Line 9: Known for its express trains, this line connects Gimpo Airport, Yoido, and Gangnam (Dunchon Oryun, Gimpo Int’l Airport, Sinmokdong, Express Bus Terminal, Deungchon, Sports Complex, Sinbanpo, Hanseong Baekje, Bongeunsa, Noryangjin, Yeouido, Saetgang KB Financial Town, Samjeon, Sinmyeongil, Airport Market, Gaehwa, Eonju CHA Gangnam Medical Center, Seokchon Hansol Hospital, Seonyudo, Sinbanghwa, Dongjak Seoul National Cemetery, Magongnaru Seoul Botanic Park, Gil-dong Ecological Park, Heukseok Chung-Ang Univ., Seokchon Gobun, Jeungmi, Yangcheon Hyanggyo, Olympic Park Korea National Sport, Nodeul, Godeok, Sapyeong, Gubanpo, Saemteo Park, Seonjeongneung, Songpanaru, Dangsan, Gayang, National Assembly KDB Bank, VHS Medical Center, Samseong Jungang, Sinnonhyeon, Yeomchang).
And then there’s Line 1, which is a monster. At 200 kilometers long with 97 stations, it’s more complex than some cities’ entire metro systems. It’s a mix of urban subway and suburban rail, with express trains and local services (Sinimun, Asan Sun Moon Univ., Gasan Digital Complex Mario Outlet, Jegi-dong Korea Association, Onsu Sungkonghoe Univ., Yeokgok The Catholic Univ., Osan Univ., Hwaseo, Jemulpo Incheon Univ., Songtan, Banghak Dobong-gu Office, Byeongjeom Hanshin Univ., Chang-dong, Gwanak Anyang Art Park, Seokgye, Dongmyo, Jongno 5o-ga Samyang Group, Sinseol-dong, Mangwolsa Shinhan Univ., Nokcheon, Uiwang Korea Nat’l Univ., Wolgye Induk Univ., Jongno 3sam-ga, Uijeongbu, Bucheon Bucheon Univ., Bosan, Dongincheon, Dongdaemun, Jiksan, Myeonghak Sungkyul Univ., Songnae, Seojeongni Kookje College, Sema, Noryangjin, Deokgye, Dongducheon Jungang, Gunpo, Yeongdeungpo, Punggi, Seodongtan, City Hall, Bugae, Seonghwan Namseoul Univ., Bupyeong The Catholic Univ., Doksan, Byeongjeom Hanshin Univ., Nogyang, Ssangyong Korea Nazarene Univ., Dohwa, Sungkyunkwan Univ., Kwangwoon Univ., Guro, Deokjeong Seojeong Univ., Gaebong, Daebang, Singil, Seryu, Jung-dong, Pyeongtaek, Sosa Seoul Theological Univ., Guro, Gwangmyeong, Dongducheon, Soyosan, Geumcheon-gu Office, Dongam, Cheongnyangni University of Seoul, Hoegi, Hankuk Univ. of Foreign Studies, Jonggak Standard Chartered, Dowon, PyeongtaekJije Korea Nat’l Univ., Jinwi, Geumcheon-gu Office, Oryu-dong, Yongsan, Onyangoncheon, Dangjeong Hansei Univ., Osan, Seoksu, Cheonan, Baegun, Seoul station, Ganeung Eulji Univ., Geumjeong, Incheon, Juan, Bongmyeong, Sinchang Soonchunhyang Univ., Guil Dongyang Mirae Univ., Anyang, Suwon, Yangju Kyungdong Univ., Sindorim, Dujeong, Namyeong, Hoeryong, Dobong, Tangjeong, Dobongsan, Jihaeng, Ganseok, Baebang).
Incheon Subway: Smaller but Mighty
Incheon has its own subway system, though it’s much smaller than Seoul’s. Line 1 runs north-south (Songdo Moonlight Festival Park, Jakjeon, Culture & Arts Center, Galsan, Bupyeongsamgeori, Incheon Bus Terminal, Seonhak, Gyeongin National University, Bupyeong-gu Office, Gyesan, Munhak Sports Complex, Bupyeong Market, Bupyeong, Central Park, Incheon City Hall, Sinyeonsu, Ganseogogeori, Imhak, BIT Zone, Dongmak, Bakchon, Campus Town, Dongchun, International Business District, Technopark, Gyeyang, Gyulhyeon, Dongsu, Incheon National University, Woninjae), while Line 2 is an automated system with two-car trains (Asiad Stadium Gongchon Sageori, Unyeon Seochang, Seokcheon Sageori, Seo-gu Office, Mansu, Geomdan Sageori, Seokbawi Market, Dokjeong, Seongnam Geobuk Market, Incheon Gajwa, Moraenae Market, Citizens Park Culture Creation Zone, Gajeong Jungang Market, Geomdan Oryu Industrial Complex, Juan, Incheon Grand Park, Majeon, Namdong-gu Office, Incheon City Hall, Geomam, Gajeong Lu1 City, Wanggil, Wanjeong, Geombawi, Gajaeul, Juan National Incheon J Valley Industrial Complex, West Woman’s Community Center). Both lines are surrounded by high-density developments and connect to Seoul’s metro system.
Seoul Suburban Rail: Connecting the Region
Seoul’s suburban rail network is extensive, with wide station spacing and express trains. These lines are built to mainline standards, meaning they can handle freight and intercity trains, including high-speed KTX services.
- Airport Railroad Express (AREX): Connects Seoul Station to Incheon Airport, with both express and commuter services (Gyeyang, Digital Media City, Cheongna International City, Hongik University, Incheon International Airport Terminal 1, Gimpo Airport, Seoul Station, Geomam, Incheon International Airport Terminal 2, Unseo).
- Gyeongchun Line: A scenic route northeast of Seoul, with impressive bridges and tunnels (Hoegi, Pyeongnaehopyeong, Kwangwoon University, Gapyeong, Galmae, Gangchon, Maseok, Byeollae, Cheongpyeong, Baegyang-ri, Gimyujeong, Chuncheon, Cheonmasan, Sareung, Cheongnyangni, Sangcheon, Sangbong, Gulbongsan, Daeseong-ri, Sinnae, Geumgok, Namchuncheon, Sangbong, Jungnang, Toegyewon, Mangu).
- Suin-Bundang Line: A massive U-shaped line that loops around the southern part of the city (Hanti, Jeongja, Taepyeong, Ansan, Migeum, Namdong Induspark, Bokjeong, Suseo, Yatap, Incheon, Inha University, Maegyo, Mangpo, Daemosan, Suwon City Hall, Oido, Yamok, Sungui, Gosaek, Guseong, Seohyeon, Wolgot, Singiloncheon, Yeongtong, Woninjae, Seonjeongneung, Incheon Nonhyeon, Jeongwang, Hogupo, Soraepogu, Singal, Seoul-forest, Choji, Gachon University, Jukjeon, Wangsimni, Ori, Eocheon, Hagik, Hanyang Univ. at Ansan, Imae, Sinpo, Songdo, Sunae, Bojeong, Cheongmyeong, Suwon, Darwol, Gojan, Moran, Yeonsu, Dogok, Gaepo-dong, Omokcheon, Gangnam-gu Office, MaetanGwonseon, Seolleung, Cheongnyangni, Giheung, Sanggal, Apgujeongrodeo, Sari, Jungang, Guryong).
Seoul Light Metro and People Movers
Seoul also has a bunch of light metro and people mover systems that connect outlying areas and major campuses. These are all driverless and use different technologies, from rubber-tired trains to linear induction motors.
- Gimpo Gold Line: A 24-kilometer line serving the Gimpo area (Gimpo Airport, Pungmu, Yangchon, Sau, Gurae, Geolpo Bukbyeon, Machang, Gimpo City Hall, Unyang).
- Seoul Light Rapid Transit (SLRT): An automated light metro line consists of Ui Line, Dongbuk Line, and Silim Line (Jongam Police Station, Uicheon, Gaori, Boramae Medical Center, Samyang Sageori, Solbat Park, Sinseol-dong, Boramae Park, Hwagye, Seoul National Univ. Venture Town, Gwanaksan Seoul National Univ., Bukhansan Bogungmun, Jangwi, Bukhansan Ui Doseonsa, Sanggye, Sungshin Women’s University, Miasageori, Wolgye, North Seoul Dream Forest, Sillim, Eunhaengsageori, Seoul Science Center, Samyang, Seoul Regional Office, Seowon, Jeongneung, Wangsimni Seongdong-gu Office, April 19th National Cemetery, Solsaem, Korea University Jongam, Buramsan, Hagye, Daebang Sungae Hospital, Danggok, Jongam Post Office, Saetgang, Boramae, Dongmyeongchogyo, Bomun, Jegi-dong).
- Incheon Airport Maglev: A short maglev line connecting airport amenities (Long Term Parking, Incheon International Airport Terminal 1, Paradise City, Water Park, Yongyu).
The Future: GTX and Beyond
Seoul isn’t stopping anytime soon. The city is building the GTX (Great Train Express), a high-speed regional rail network that will revolutionize urban transportation. With three lines and average speeds of 100 km/h, the GTX will connect Seoul to its suburbs and beyond, making it one of the most cohesive transit networks in the world (Suseo, Dongtan, Yongin, Songpa, Gwanggyo, Jije, Seongnam, Pangyo).
Other projects include extensions to existing lines, new light rail systems, and even a tram line. By the time all these projects are done, Seoul will have over 700 rapid transit stations—making it one of the most impressive urban rail systems on the planet.
Seoul’s transport system is a marvel of planning and engineering. From its dense metro network to its sprawling suburban rail lines, the city has something for everyone. And with projects like the GTX on the horizon, Seoul is poised to give cities like Tokyo a run for their money.
If you’re into transit systems, Seoul is a dream come true. And if you’ve made it this far, you’re probably as fascinated by it as I am. So, next time you’re in Seoul, hop on the subway and explore—you won’t regret it!