Item description:

An old underground complex with many control room, lots of elevators, gateways (and one auto-rotative), treadmill for some oildrums, lots of cameras (in all important rooms).
In the teleportation room, you can choose your destination (there is a control panel) Dest 1 : to the rocket launcher; Dest 2 : To the Oildrums room; Dest 3 : to the overwatch room.

There are some ducts, but I use a teleportion system to shorten distances in ventilation ducts.

For one elevator, there are two doors face to face, so when elevator stops and you see that the door remains closed, watch the door behind you.

Oh, and in the Teleportation room, there are some holes with a light above. If the red light is on, throw a grenade through the hole to teleport it to the area where a player is.