Portal
This is a simple portal to look or shoot through walls.  It would be great to use these in CTF or some other team oriented map.  The portal moves with a button because it will do damage.  If you get pinned when it swings open, you may die.  If you place more than one in a level, remember to change the TEAM key for the FUNC_DOOR_ROTATING.
 
The prefab includes the button, so also remember that it has TARGET and TARGETNAME keys if you use more than one (wall, room, lights and RL not included).