It appears to be Bundang Korea District Heating Corporation(?)
A scene from the first rooftop where you can see the apartment complex with the transmission tower and the mountains behind it.
If you look at the apartment from the rooftop of the circular building, it will look like the composition of a music video, right?
In the second factory scene, the pump(?) is surrounded by something yellow.
Naver blogger's review of the tour... You can see the pump(?) surrounded by yellow even inside the actual factory.
Maybe that's right?