We took the public bus to Taeha, then took the monorail (4000won per person) up the mountain to see the coastal view from Daepunggam. It is very windy up there, and the view is stunning as well.
We took the old walking trail down hill, which is very beautiful as well (recommended).
We took a taxi from Do-dong to CBS relay station (the driver probably rip us off by charging 10000won without running meter).
The path is beautiful and well marked, reaching Seonginbong peak within 3 hours.
It took us less than 2 hours to ascend to Nari Basin and took a bus at 11:50am to the main bus route.
One of the highlight tour in Ulleungdo, walking from Do-dong to Jeo-dong (about an hour). It's beautiful.
Our first meal of Octopus intestine hotpot at 10000won per person, not bad (we didn't know it was intestines when eating).
50000won per night on weekday, quiet and clean, with free drinking water refill available, very near the ferry terminal and bus stop.
Ulleungdo seems like a touristy place for locals, the ferry seems 95% occupied on a weekday.
The ferry stop at Do-dong, with plenty of accommodation around 50000won per night on weekday. Drop by the Tourist Information for map and bus schedule.