This map compares two types of "built" open space at USC campus:
the red represents concrete courtyards defined by buildings arrounding them;
the purple represents the green open space defined by building boundaries.
This drawing compares the access to types of open space:
top two are green open space are defined by buildings surrounding them, and have paths leadind to its center.
Bottom two are concrete courtyard space inside or partially inside another building theresore people need to enter the door.
