3.5 hours! 1.5 hours from Gwangju to Seoul (by bus) and another 1.5 hours from Seoul to Daegu (on the high speed train).
The farthest I went was from Cheorwon (near the DMZ -- the border with North Korea) to Jeju Island. This is pretty much as far north and as far south as you can go in South Korea.
1) 70 miles (2 hours) from Cheorwon to Seoul (driving/on the train).
2) 280 miles (1 hour 10 mins) from Seoul to Jeju Island (flying). We then drove another hour south, to the southernmost edge of Jeju Island.
Public transportation is amazing in South Korea, so I took the bus and subway, as I usually do!
When I visited Daegu, I explored Seomun Market, which is the largest traditional street market in Daegu and one of the most famous markets in South Korea.
When in Daegu, I stayed in a hanok (house) that had been preserved in the middle of the city. It was not a 100% traditional hanok because it's design was influenced from the preceding Japanese colonization of Korea, but it still had many traditional elements like pine columns and roof supports, a clay tiled roof and heated ondol floors.
