Three Hours in Gangnam

Start at Samseong Station, take in COEX Mall and Starfield Library, then cross the road to Bongeunsa.

1. COEX Mall (60 min) — all underground, so weather never matters.
2. Starfield Library (30 min) — the photo stop.
3. Bongeunsa Temple (60 min) — temple roofs against glass towers.

Distances are short, three hours is genuinely enough, and you can exit at either Samseong or Bongeunsa Station.