In the room with the wobbly 'UAC' walls, there is a very discreet door to a secret room.

Inside the secret room from #1, at the far right, there is a switch on the wall. Hard to see, as the room is nearly dark. The switch is a door to a secret room with goodies.

Just before you get the blue key, there is a few steps up to a couple of windows overlooking the open area with toxic waste. At the end of the rooms, there s a flight of steps down to a switch. When you activate it, a secret door open right behind you.

Past the 'cross' room and the next corridor, there is a small concrete room with some toxic waste pools. There is a exit at the back, to the right. It leads to a secret room. If you already have the red key, take the teleporter to the next room...

...cross the room, and open the red door. Small room when you step inside: the secret. When you press the switch, you enable secret #6.

Inside the blue door, turn left and keep right all the way to the top of the stairs. A room with a toxic pool, two doors and a switch. Together with the red-key switch in #5, it opens a secret room right next to the entry.

There are no secrets in E2M8: Tower Of Babel