I want to know the answer to the following question:
In addition to the New Haven Harbor, what additional natural element is a prominent geographic feature of the area, flanking the northeast and northwest boundaries?
All the background I'm provided with is that "West Rock has been tunneled through to make way for the east-west passage of the Wilbur Cross Parkway (the only highway tunnel through a natural obstacle in Connecticut), and once served as the hideout of the "Regicides" (see: Regicides Trail).". Is that enough to answer the question?