University president Amy Gutmann called it a "beautiful, sustainable, green oasis."
Mayor Nutter, an alum of Penn's Wharton School, told the assembled dignitaries that he regarded Penn Park as "one of the most incredible projects this city has seen in decades."
A majority of the land used to be a parking lot for the U.S. Postal Service. Penn bought the site in 2007 and combined it with neighboring parcels to create the sprawling park south of Walnut Street.
Steve Bilski, the university's athletic director, said the facilities would help serve the university's many sports teams, including club and intramural squads that long have suffered from a lack of available playing fields.
Xinran Wang, 18, a sophomore who plays with the "Ultimate" disk club (they're not allowed to call it Frisbee, which is trademarked), said the park was great for all the sports clubs. "Being in the city, it's hard to find a lot of field space for all the teams Penn has," Wang said.
Rachel Sebastian, 21, a senior and member of the women's soccer club, noted all the athletes playing and spectators milling about. The club is not used to having many people watching.
"It's weird seeing so many people out here," she said.
Penn's rugby club sometimes practiced under nearby train tracks and even as far away as Clark Park at 43d Street and Baltimore Avenue, said club member Sawyer Waugh, 19, a sophomore.
"This is certainly a pretty nice upgrade," Waugh said.
Contact staff writer Robert Moran at 215-854-5983 or firstname.lastname@example.org.