http://en.wikipedia.org/wiki/Central_Park has some good information about it.
New York City's need for a great public park (Central Park) was voiced by the poet and editor of the Evening Post (now the New York Post), William Cullen Bryant (yep, the very same man I put in my story!)
This information is from wikipedia:
Bethesda Terrace overlooks the lake in Central Park. It is on two levels, united by two grand staircases and a lesser one that passes under Terrace Drive to provide passage southward. The upper terrace flanks the 72nd Street Cross Drive and the lower terrace provides a podium for viewing the Lake. The mustard-olive colored carved stone is New Brunswick sandstone, with a harder stone for cappings, with granite steps and landings, and herringbone paving of Roman brick laid on edge.
The pool is centered by a fountain sculpture designed by Emma Stebbins in 1868 and was unveiled in 1873. Stebbins was the first woman to receive a public commission for a major work of art in New York City. The bronze, eight-foot statue depicts a female winged angel touching down upon the top of the fountain, where water spouts and cascades into an upper basin and into the surrounding pool. It was the only statue in the park called for in the original design. Beneath her are four four-foot cherubs representing Temperance, Purity, Health, and Peace. Also called the Angel of the Waters, the statue refers to the Gospel of John, Chapter 5 where there is a description of an angel blessing the Pool of Bethesda, giving it healing powers.
This is the underground passageway that absolutely captivated me, and where I could see Isabella and Edward squaring off. So beautiful, and I love that you can see the fountain at the end of it.
More info on Bethesda Terrace and fountain: http://www.nycgovparks.org/parks/centralpark/monuments/114
If I ever go to New York again, I am stopping here! ;D