Control of nature required not only manipulation of the surface of Central Park, but changing the foundation underneath the ground the park was built on top of. Before construction of the park began, the park land was a mix of rocky, infertile soil and swampy wetlands. To create the pastoral, the soil needed to be fertile and water needed to be contained within lakes and ponds. By changing the foundation of the land itself, Central Park is the ultimate pastoral because it not only represents man's control of nature, but is that control and harmony made reality.
The construction of the Lake required ingenous planning not only of what would look beautiful, but how to control the land into creating this beauty and maintain the illusion of naturalness. Surrounding the lake, underneath the soil, is an elaborate drainage system that works maintain a pleasing water level in the lake.
Such technology is what makes the surface of the park actuality. Central Park is not just a sculpture of surface nature, but an insertion of culture's technology beneath the art of the landscape itself. While appreciating nature, one is walking on top of culture's most anti-nature innovations.
The tunnels were carved through huge outcroppings of solid rock, held up by retaining walls, on top of newly constructed foundations and hidden by a line of trees, or planted on top of to further prevent them from being a part of the park goer's landscape.
The tunnels and drainage systems of Central Park -- the Underground Systems -- were as much a part of the visitor's experience as the Ramble and the Lake. They were hidden structures that made the artifice of the surface possible.