Hello, Since you are new to mapping. I would like to tell you few tips
-Map maps with sence, use Law of pysics. Map must be at some good suitable place.
-Must check bugs after you finish mapping.
-If you are going to map group/clan base then map must look like group base, not a airport.
I found few bugs and I want to show you.
1) Bug with Glitch. you messed with world object and changed its place.
http://i.imgur.com/Ii7Movc.jpg
also this pool object floating around.
http://i.imgur.com/XA1Cw2M.jpg
2) whenever you add building/stairs or anything four,three or two sided then must set "doubleside" as True
http://i.imgur.com/1SkwGUr.jpg
also use suitable object.