Sokcho to Busan
Recommended! Beautiful scenery, enough chances to take a swim, a lot of resting places and gorgeous viepoint. The night skies were pink, purple and blue!
Some ascents were pretty intense, but if you are in good shape this route wouldn't be an issue.
Check out pictures and details at: http://www.judithdw.nl/cycling-from-sokcho-to-busan/