A couple shots of oakleaf hydrangea (or Hydrangea quercifolia) below.
As you can see from the foliage or guess from the species name, the leaves of this plant almost look like giant oak leaves. Quercus means 'oak' and folia means foliage or leaves. Thus, oak-leaf hydrangea. In autumn, these leaves will turn a deep bronzy-red, ultimately falling to reveal a fibrous, exfoliating bark.
The flowers are similar to a mophead hydrangea, though this plant only is available with a creamy white blossom that slowly turns pink. Like many plants, this flower's showiest part is the set of four bracts that radiate from the actual reproductive parts of the flower.
I took these en route to the park last night, but unfortunately the photo of the plant's habit was taken in a rush, and is disappointingly blurry. I'll include it below, just to give you an idea of the size and shape of this lovely plant. The specimens below are most likely a straight-species, though cultivars are available of dwarf plants which that better fit small locations.