It is a non-linear map which have many paths to take and reach the end. The point is, that you play a map one time and you are happy. Then you have a little break in Portal, because there aren't any new released maps for some time. But the answer is here: play the Deja-Vu again, but choose a different path with different puzzles. You can choose freely the way that is going to lead you to the end. Thats it!
Looking intressting dosen't it?
It got me wondering what's inside.
I'm already ctrl+w :)
I would not go there , the only thing that holds the gate is that box, maybe its a turret storage.
Malfunctioning turrets. Perhaps I can get them to shoot at GLaDOS during the Boss Fight, assuming they don't get disintegrated on contact with the emancipation field.