Yeah, it said that I recognized the place because I had been there many times before in a nightmare that kept on coming back when I was like 8 or 9 years old.
It was definitely influenced by playing Doom and Quake (I had another dream where I was in E3M6) at the time. One other feature that got into this dream was an entrance to an old-time shelter near my granny's house. It always kept me wondering what could be hiding inside, when I was a kid.
After "visiting" the bunker several times in the dream, I was able to control what I was doing.
In the dream, once I entered the bunker it seemed there was nobody inside, other than the old equipment and supplies but seemed to be work. Further inside I discovered a deep, large shaft with a cargo lift (not yet functional in the video below) and a ladder. At the bottom, there were two doorways, one small with pipes and cables, the other looked like the main tunnel, but with the view obstructed by a sharp corner. There was a flashing light coming from the main tunnel.
As I got closer to it, a shadow of a giant humanoid figure appeared in the flashes from around the corner, followed by grunting, growling, and monster-like screams.
Most of the times, this was the moment I got scared and ran back to the lift or climbed the ladder. But sometimes I just waited, or went through the small corridor. One time I tried to see the monster but as soon as I turned the corner, I woke up. I was the monster all along, I guess. :D
I've skipped the making of the actual start of the nightmare - entering the shelter - until recently and recorded it: https://www.youtube.com/watch?v=qPtMixJIkrA.
It is still a work in process, but the main mechanics are there. I've added some "extra features" to make it more pleasant for the player to enjoy a visit to my subconscious.
Let me know what you think about it.
Fun fact: the video title says "a nightmare" in Czech, pronounced something like "notshnee moora".