" I love having a mix of city life with more natural parts."
Since you are willing to look outside the Northeast, take a look at Colorado College. Smaller school, small classes. Strong in fine arts and psych. Walking distance to downtown Colorado Springs. Very outdoorsy student body and plenty of access to nature and outdoors pursuits. Much more sunny than the Northeast even though both get snow. It does have a unique academic calendar structure with the block plan.
You can also look at places like Haverford which has its own bucolic campus with a arboretum, but you can access all the urban amenities of nearby Philly via a short commuter train ride of 20 minutes or so. The train is within walking distance from campus.