경기장 (I got help recognising it)

It means stadium, likely alluding to the western terminus. The branch is probably 와우도 on the destination signs given the prevalence of the name for the residential neighborhood and local placemarks in http://38northdigitalatlas.org/

The destination sign in https://transphoto.org/photo/1408280/ could plausibly be '경기장' as well, but it would mean that the operator didn't change the destination sign at the end of the route. This practice is very common in america, to the point that a commenter noticed the wrong destination in a historical photo https://www.sfmta.com/blog/munis-clean-a...urns-75

Update: Eastern terminus is 상대두 based on a still shot of a trolleybus stop from KCTV.