hmmmm....
My first map that wasnt a very oversized room with an wall missing must have been... Lab!
The maps name was lab
had no story you started in an big room(oversized, of course):D with an mp5 2mp5grenades 3batterys an glock+crowbar and then you had to walk thru an xen area which actually jsut was an square room with some xen textures(which didnt fit at all) some headcrabs and then a slave, i think but that time i didnt know how to make doors NOT move at the z axis so all doors moved the same way (which made a big problem) because after the the xen area the doors would move towers you and not inside to the side
!
Then some offices which was just square rooms with an desk that was larger than the scientist standing behind!!!