Massachusetts
Most Beautiful → Smith College
Smith College is an arboretum. The landscaping was designed by Frederick Law Olmstead (who also designed Central Park in NYC). It includes a beautiful lake (Paradise Pond), botanical gardens, interesting architecture, and even waterfalls. It's also gorgeous in the New England Fall.
Here are some pictures:
Campus Photos Botanic Garden at Smith College, Waterfall Photo Milescapes- Gifts, Original Artwork and Photography [Smith College]