The planting plan was designed to provide viewing corridors toward the city, with visitors enjoying 360-degree vistas from the top of Outlook, the tallest hill, and scenes of the Financial District skyline from Grassy Hill, seen here. Some 830 trees from 32 species selected for their size, color, and heartiness—including a variety of oaks and sassafras—were planted on The Hills, with a mix of balled-and-burlapped and container techniques.