I went with my family for 2 days and 1 night on September 26-27.
Take the Seoraksan cable car.
Ulsan Rock
It's Gwongeumseong Fortress, but I don't know where the fortress site is.
Accommodation lake.
Stay overnight and go to the beach to catch the sun.
Naksansa Uisangdae.
Hongnyeonam.
Goseong Beach.