People in West Philadelphia will look across the Schuylkill River and see one of the best views of the Center City skyline.

People in Center City will look across the river and see a tantalizing 24 acres of open green space.

On Thursday, the University of Pennsylvania will open a new park on the west bank of the Schuylkill River. Penn Park is beneath the Walnut Street Bridge and extends down to the South Street Bridge on land that had been used as a parking lot for the U.S. Postal Service. It cost $46.5 million, none from public funds.

There are tennis courts, two artificial-turf playing fields, and a small stadium, all interspersed with lawn. The park near the swollen Schuylkill has already proved itself.

"The absolute greatest test--which I could not have anticipated--was Hurricane Irene," said  Amy Gutmann, president of the University of Pennsylvania. "Penn Park passed it with flying colors. We have developed a state-of-the-art cistern system; it's not visible. It's under the fields. There is almost no erosion, and 500 trees, which we planted just before the hurricane, all survived."

Penn Park is the centerpiece of Gutmann's ambitious plan to reach out to Center City. The next project is a building now under construction for the engineering school--a nanotechnology center--that will act as a Walnut Street gateway.