If you came to Gangnam with someone having a procedure, you may suddenly have three hours, or a whole day, to yourself. Most clinics sit within a short radius of Gangnam Station (Line 2 and Shinbundang), Sinsa Station (Line 3), Apgujeong Rodeo Station (Suin-Bundang Line) and Samseong Station (Line 2), so wherever you wait, you are usually two or three subway stops from the door you need to return to. Download Naver Map or KakaoMap before you start: Google Maps gives limited walking and transit directions in Seoul.
1. Somewhere to sit for hours. The easiest base is COEX Mall, connected underground from Samseong Station exits 5 and 6. Starfield Library inside it is spectacular but busy with photographers, so it is a place to look at rather than to work in; for a laptop and a charger, use the cafe floors deeper in the mall. Power outlets go first, so arrive in the morning if you need one. Free Wi-Fi is generally available in the mall and in stations, but speeds vary, so bring a SIM or eSIM if you have calls to take.
2. Eating alone. Solo dining is completely normal here and nobody will look twice. Avoid Korean barbecue places, where meat is often sold from two portions up, and head instead for noodle, kimbap or rice-bowl counters, the food court under COEX, or a department store food hall. Between roughly 12:00 and 13:00 the office lunch rush fills everything, so eat at 11:30 or 13:30 instead. Cards work almost everywhere, but some small shops reject foreign-issued cards, so carry a little cash.
3. Walking and shopping. Garosu-gil is about five minutes on foot from Sinsa Station exit 8, and from there it is roughly a twenty-minute walk over to Apgujeong Rodeo Street. Galleria and Hyundai Department Store are the nearby full-service options; take your passport and use their tax-refund desk. Smaller purchases can be refunded immediately in store and the rest is processed at the airport kiosks, so keep every receipt. K-Star Road, near Apgujeong Rodeo Station, is a short and easy loop.
4. When you want quiet. Bongeunsa Temple sits across the road from COEX, about five minutes' walk, and there is no entry fee. Seonjeongneung, close to Seolleung and Seonjeongneung stations, is a wooded royal tomb park where an hour or two on a bench passes easily. Dosan Park, walkable from the Apgujeong side, is small but fine for a pause. Everything gets busier at lunchtime and on weekends.
5. Getting back fast. The subway is the reliable option. Traffic across Gangnam is heavy on weekday evenings between about 18:00 and 20:00, so add thirty minutes if you plan to take a taxi. Ride-hailing apps sometimes refuse to register a foreign phone number, so asking your hotel or the clinic desk to call a taxi is often quicker. One last thing: phone contact from inside a clinic can be patchy, so agree in advance on a meeting point described by station exit number. It makes the whole day simpler.