The first day I would build
Give the city one clear route before adding extras.
- Start with Daewangam Park and Taehwa River Grand Park while energy is high.
- Use Jangsaengpo Whale Museum as the natural reset instead of crossing town too early.
the easier plan is Taehwa River or Daewangam first, Jangsaengpo or Ilsan Beach later, Samsan-dong for food. That keeps the day readable instead of turning every good name into a separate detour.
I would rather leave one place for tomorrow than drag a tired route through Ulsan Grand Park just because it looked close on a map.