In the Goldeneye movie, the Depot was a very minor "level". I actually wouldn't have considered it to be made into a level in the game. But it was, and it's a fairly large level.

You can see the size of the level, and all of the empty garages. There are also trailers parked nearby. Was all of this added, just to make the level seem like an actual, real life Depot? Probably. Still, the size and the objectives were added, so it would actually be a level that would take more than 5 seconds to beat.

Okay, here's what looks like an old train station. It's all boarded up. I doubt that you ever reached the train from here though. It was likely put here as a misleading building, to get you to try and go around it, and eventually find the actual building to get inside the train.

Down an alley, a fence, where you can see another part of a level. Why a fence? Why not a wall? I guess we'd then be asking why they didn't put a fence instead of a wall... I have no idea.

Inside the Depot train building, there's an old Archives light fixture. As well as an Archives door. These doors could have been placed in many other levels, until other doors were made. Since this is an out of the way part of the game, it was probably just left the way it was.

Upstairs in the train building, the windows are boarded shut. They were probably never open in the first place. Also, there is a roof window. For what? Probably just another detail thing. Rare added a lot of those.

The obvious way to get to the train... LOCKED. So you just go around, and up the stairs. Why even put a door here? Was it to lead you upstairs to find the safe? It was likely opened at one time, then just locked so you would need to go upstairs and come across the safe.

Here's a look at the main part of the train building. You can see Beta glass on the ceiling. The windows are just there for completion, but why weren't they changed to normal, breakable glass? It was probably just easier to leave them that way.