CI is a Half-Life 2 modification that centers around the events directly after Half-Life 2 (during/after the Episodics).
Second to last floor in Nova Prospekt Zero. This is the main prison area.
Each section of the three mini-floors represents a Cell Block. Decals were placed above doors to indicate which cell block they lead to.
Most floor to floor movement is done via teleporters and stairs.
Lighting has been fixed.
This is just my opinion, but personally I don't feel that cylindrical shapes fit in with the conventions of combine architecture.
its not that they are wrong, but he used a rusted texture on it, an that really doesn't look right...