At first, the door does not want to seem to move but, after realizing that the door doesn't really fit the frame that well and tends to stick shut, you give it a solid shove and the door swings into the building.
The interior is mostly dark, although light is now entering through the door and a bit is filtering in from above. This is a mostly circular space about 40' across, there are carcasses for upper and lower cabinets arranged along the walls as well as one to the right of the doorway. To your right is an angled wall with another, lighter, door in it. The door is currently closed.
The floor looks like it is in the process of either having tile placed or removed and, looking up, you can see a large hole in the ceiling that is currently covered with some boards and, presumably, an oilcloth to keep the rain out.
From somewhere deep in the building you can hear a steady roar and it is easily five to ten degrees warmer here thn it was outside.