Secret Places (3)
The box above the blue access card opens (it says "Top Secret" on the side of the box).
There's a secret floor above the comedy club. Fly into the window above the word "Boner" on the sign. There's loads of explosives up here.
This is in the room which is inaccessible until the water level has been raised. Hit the switch into the "locked" position (left side of the image) to open a secret place containing a shrinker (right side of the image).