I like the detailing - the broken pillars are neat.

There are a couple of things that make this look very much like a  map rather than a real place.  Often maps try to look real, to make them feel more immersive.  If not, they usually go for a very obviously "unreal" theme - such as a cartoon.

If you want to make it feel like a real place, don't hollow out a giant box to contain your level.  Also, don't make supporting walls and floors paper-thin.

Well just because I like it doesn't mean it was right

What I meant by the detailing is those broken bits of stone and pillars.  You can see them best in the first shot, on the right.  They make for interesting shapes - the rest of the map is pretty boxy.

Just spotted the slightly bumpy terrain; again, I think this is good because it makes the map look less like a box and more like a place.

Er sorry, I meant to say LAST shot not first.

/slaps self

heh, my first map one of my friends came over and attempted to use Worldcraft as a 3d modeling tool to construct a giant stone statue out front of a building.  Without windows.  I assume r_speeds were through the roof, and it had a lot of errors.  A 'fro made of spheres is something you should avoid in Hammer... Also the floors were paper thin, the lighting was entirely light_environment, and weapon placement was horrid.

Meeeeeeeeeeeeeeeeeeeeeeemorieeeeeeeeeeeeees...

Just a few points which may help make your maps a little better..

• Crates. Ok, crates exist, but not in vast quantities spread over several places (unless it is one giant storehouse). Try and use other things to fill up the space, take a look around when you next pass construction sites and so forth..
• Shot #1. The outer wall of the building looks paper thin.. for realism, make it thicker - the whole place would collapse with walls like that. Also, ( I think ) thicker brushes compile more quickly!
• Shot #1. Doors/Windows. Frames for doors and windows, even if texture based rather than extensive detailing with brushes helps to break up the monotony and make it feel "real".
• All shots. It looks like a (fairly simple) compound of some kind for the military.. ok, it may be your first attempt and a little lacking but it is a good theme to play and experiment with. Try adding roads, make the outer wall go round corners and raise and lower. Add guard booths, "uniform" barracks.. Try and cut the empty space down and turn into something which looks and feels more real. Just have a look at films with this kind of thing on, I'm sure theres good war films with this kind of location! If not, try Opposing Force, take a look at the bootcamp
• Shots #3/4 - texturing, ok, BUT you have the same ceiling texture as the walls (it looks that way anyhow). Look through the WAD files, find some textures which are different colourations but match. It's simple changes like this which make the place feel like it has been "constructed" for real, rather than just thrown together in a mapping program. Find textures which look like floors and ceilings. And to liven up the walls, simply add some pillars here and there. Beams/Girders are also good for breaking up "box" rooms! 
• Try downsizing your main feature buildings - make them different heights, but bring them closer together. This raises potential for walkways and paths between the two! All makes for a good fight!
• A lot of stuff there, but pretty simple and easy to execute, that even the best mappers dont ignore (dont quote me on that ). Keep at it, read through the tutorials here and on other sites, and please keep mapping and coming for feedback!

 Bummer, i just lost a big post....well all im going to say is that this is a new map that stays away from boxes and has original ideas, like a grave yard suspended 40'000 ft up in the air. 

Heres the pics....

First shot: Bottom level, there are 2 more of those style bases on the bottom floor, each in a differnt pattern of being built.

Second shot: Close-up of the graveyard, second floor.

Third shot: Right half of the second floor.  Side of grave diggers hut is shown. 

 Fourth shot: The left half, is brush and some trees.

Fith shot:  The top floor of the level.  Yes i know its bare, but thats how i wanted it.  Its basicly a great place to have a showdown....i have tested this out thouroughly.

Nice triple post!

BTW - what are the r_speeds for these images?  (if you don't know what that is - go into the console and type r_speeds 1 - it's recommended you keep the "wpoly" number below 700.)