Restored stream runs central Seoul City Hall to Dongdaemun, honestly best urban running in city. Completely flat, well lit at night, water features and art every few hundred meters.

Start Cheonggye Plaza near City Hall station lines 1/2, run east far as you want and turn back. Full route Dongdaemun about 8km round trip. Early morning 6-8am perfect - locals doing tai chi, cleaner air before traffic.

Public restrooms and water fountains every km. Stream level 3 meters below street so running in cool urban canyon while city bustles above.