A section of Prospect Park's interior is known as the Ravine. The region contains the headwaters of the park's water system, as well as Brooklyn's only remaining old-growth forest, the Midwood. Olmsted and Vaux saw the Ravine as the heart of Prospect Park and the centerpiece of mountainous tableaux similar to the Adirondack Mountains, and designed it in a similar fashion to their Ramble in Central Park. The perimeter of the area is a steep, narrow gorge. The watercourse goes through the Ravine en route to the Boathouse.