Seoul Arena concerts — getting there and the last train

1-23 Changdong, Dobong-gu, Seoul

Indoor arena

View on Google Maps

…

Getting back

For what is actually running tonight, the map apps are the accurate answer. Below is what they cannot tell you.

Nearest station

Chang-dong Station 창동역 (Lines 1 & 4)

Last train, weekdays 4호선 24:58 → 불암산 · 24:30 → 서울역· weekend 4호선 24:01 → 노원 · 23:31 → 서울역

These times come from the published timetable. Trains after midnight are written as 24:00 and later, exactly as the platform boards write them. Holidays and special schedules change them, so confirm once more in a map app on the day.

Open in Naver Map Google Maps transit

Near here, after the show

Late food Cafés Pubs & bars Clubs

Clubs fill up after 10pm and run until dawn. Bring your passport — the door will check ID. Entry policies vary from place to place, so it is worth having more than one in mind.
Last subways vary by line but generally go around midnight. Shows usually end between 10 and 11pm, so leaving promptly you will normally make it — it is the merch queue and the photos that cost people the train.
After the subway stops, night buses numbered with an N run until roughly 3–4am. Your T-money card works on them, and the routes show up in any map app.
The street outside a venue at closing time is the hardest place in the city to find a taxi, and the hailing apps usually want a Korean phone number. Walking five minutes to a main road is normally faster than waiting.
Look up your way back before the show rather than after it. Afterwards you will be in a crowd, on the move, with no room to study a screen.