Bread, how you make maps is by using a program called hammer world editor. It's in the GMOD bin file.When you get into the hammer editor just look up tutorials.

HOW THE HELL DO YOU BUILD A MAP?

Don't you remember those old gmod times?
Yeah, this gives me flashbacks

Awesome!

a nice big flat box map perfict for me for those big duplacats
if you want to im press me try making a multi floor version of this like one floor is flat one is bumpy one is part water etc try it! it will be fun