Free: All time
For those travelling in Seoul and are in need to make domestic phone calls, keep an eye on the “Digital View” booths that are available in almost all the city’s major metro stations. The calls are free of charge to any landlines and mobile phones. On the same booth, there’s also a touch-screen map that works fairly similar to Google Maps. The functionality includes street views and shops and restaurant suggestions.
Website: seoulistic.com/quick-tip/how-to-make-free-phone-calls-in-korea
Photo credit: Seoulistic