The exit number is the address: how Seoul meets, and moves, by chulgu

You are standing at the foot of a staircase, phone in hand, reading a message that gives you no street and no building — only a number. Meet me at Exit 6. Around you, other people are doing the same thing: checking a digit, turning, climbing. In Seoul, this is not vague. The number is the most precise instruction the city knows how to give.

The number is the address

Every underground station in Seoul threads to the surface through numbered doorways called chulgu (출구), and the numbering runs in an unbroken loop around the station. Ask a Korean where a café is and they will rarely start with a street; they will say the station and the exit — Euljiro 3-ga (을지로3가), Exit 4, then left. The exit is treated as a fixed coordinate, more reliable than an address a foreigner cannot pronounce and a taxi driver would rather not parse.

This is why shop listings, event notices, and the directions a friend types out all end in a number. A bakery near Hongik University Station (홍대입구역, Line 2) will describe itself as three minutes from Exit 9, not as a lot number on a road sign. Once you accept that the digit is the anchor, half of Seoul's navigation stops being guesswork.

Why the wrong exit costs you

At the larger stations the exits are not a matter of a few steps' difference. Gangnam Station (강남역, Line 2) sends more than a dozen exits up onto opposite sides of a road wide enough that crossing it on the surface is its own small journey. Choose the exit facing the wrong way and you climb into daylight, realise the place you want sits across ten lanes of traffic, and go back down to cross underground — the thing the numbering was trying to spare you.

Transfer stations make the stakes plainer. Express Bus Terminal (고속터미널역, Lines 3, 7, and 9) spreads underground for what feels like a neighbourhood of its own, with exits surfacing near the bus terminals, the department store, and the underground shopping arcade, each a long walk from the next. The right number puts you at the door you need. The wrong one puts you a five-minute corridor away, luggage in tow.

Reading the number before you climb

You do not have to guess. Inside every station, yellow signage lists what sits above each exit — the bank, the hospital, the bus stops, the neighbourhood landmarks — so you can match your destination to a digit before you touch the stairs. Near the turnstiles there is usually a large board with a map of the surrounding blocks, each exit marked and labelled in Korean and English.

Direction matters underground too, because at a station like Jamsil (잠실역) the platform stretches far enough that the nearest exit depends on which end of the train you rode. Follow the overhead arrows toward the exit block you want while you are still on the platform, not after you have climbed a set of stairs and committed. The signs count up and down as you walk, so if the numbers are rising away from your target, turn around.

How Seoul agrees to meet

The exit is also the city's default meeting point. Friends do not text a café and hope both find it; they name an exit and gather at its mouth — Gangnam Station Exit 10, the plaza outside City Hall Station (시청역), the wide landing at Exit 2 that locals use as a rendezvous. Stand there for a few minutes and you will see the pattern: people waiting, phones down, watching the stairs for a face.

Pairing the number with a visible landmark makes it foolproof. Say the exit and then the thing beside it — the pharmacy, the bus shelter, the convenience store on the corner — and neither of you has to describe a building you have not seen. At Samseong Station (삼성역), where the exits feed into the COEX complex, naming both the exit and whether you mean the street or the mall saves a long loop.

Getting the number right

When you search a place in Naver Map (네이버 지도) or Kakao Map (카카오맵) — the two apps that actually route inside Korea — the result names the station and the nearest exit, and the walking line begins at that exit rather than the station centre. Trust that number over a memory of the last time you were there; exits get renumbered and rebuilt when a station is expanded, so confirm on the app or against the station's own board rather than assuming last year's layout holds. What a walk actually costs in time depends on the station's size, and the app's estimate is the honest one.

The mistake to avoid is climbing the first staircase you reach because you are tired of the corridor. At a sprawling station that single wrong choice can mean surfacing on the far side of an intersection with no crosswalk, then descending and crossing underground anyway. Read the exit number first, walk to it underground where the air is level and the signs are lit, and let the digit do the work the city built it to do.

약속은 대개 이렇게 정해진다. 무슨 역, 몇 번 출구.