I'd say Penn. I'm thunderingly biased, of course. But Penn is about as green as an urban university is going to get.
And they're building even more greenspace on what used to be parking lots and US Post Office buildings. Check out the master plan
Penn Connects : *—*Home
Oh and check out the biopond--an amazing hidden urban gem.
UPenn - SAS - Department of Biology - Biopond UPenn - SAS - Department of Biology - Biopond