Investigators say the attack took place here on the jogging path that runs along the Schuylkill River near the Art Museum and Fairmount Park.
"That's frightening, you know what I mean," a woman out walking her dog near the trail told Fox 29 Monday. "I'm not usually out at that time of day."
"It scares me a little bit," said one runner.
Detectives say the victim was a University of Pennsylvania student out for an early morning run along this isolated part of the jogging trail that runs just below the museum and out onto Kelly Drive.
"It's good to know to be more aware," said runner Katie Creran
"I just look to see who's around," said one woman walking in the park.
Creran is a student at Penn, she was out for a morning run Monday when she heard the news about the attack. She jogs along the trail on a regular basis.
"I used the be a rower, so I've been around here all the time, but I don't usually feel that unsafe," Creran told Fox 29.
"I always think of it as pretty safe, there are usually a lot of people down here," said the woman walking her dog.
The sexual assault here brought back memories of the Fairmount Park rapist, who first struck more than 10 years ago in April 2003, then in July and again in October of that year.
Medical student Rebecca Park was raped and murdered in the July attack. Four years later, DNA tests showed a rape in Pennypack Park was committed by the same suspect. No one has ever been caught.
"Pretty much anyone running by I look at to see if there's any reason for me to pick up the pace," Creran said.
"You do have to be careful whenever you're getting close to dawn or dusk I think."
No further details on the attack were released by police.