They sleep there, often leaving behind them the cardboard boxes and newspapers they use as bedding and other odds-and-ends. That trash joins the soda bottles, fast-food containers, and other detritus that visitors don't bother to throw in one of the area's many trash cans.
Skateboarders defy a ban on practicing at LOVE Park, leaving trails of black wax on the edges of walls and destroying the granite plaza stones, which are expensive to replace.
It's almost as if there are two parks. At night, skateboarders thunder across the granite, and the homeless congregate for meals and move in for the night. On a recent night, a teenager drew on a wall with a black Sharpie without apparent fear of prosecution.
By the time Figlestahler finishes sprucing up in the morning, the park is ready for the crowds who swarm there to buy food from lunch trucks, lounge around the fountain, and listen to bands that perform in warm weather.
"At times it can't present itself in the best way. At times it looks beautiful," said Mark Focht, first deputy commissioner for Parks and Recreation.
The park's appearance is crucial to the city's image; tourists flock there to pose in front of Robert Indiana's celebrated LOVE sculpture, with the view it offers of the elegant Benjamin Franklin Parkway.
Empty potato-chip bags are not supposed to be part of the picture.
Figlestahler, a trim 50-year old who has worked for Philadelphia's parks for 22 years, doesn't dwell on the bad behavior.
"I don't know what it is with people's attitude here," he said. "It's everybody's backyard. It's everybody's job to keep it clean and nice."
When he arrived at work early Tuesday, three men were sleeping under the park's saucer-shape visitor center, and two people, their faces covered in blankets, snoozed on grates on the side that borders 15th Street.
No one is supposed to be in the park between 1 and 6 a.m., but enforcing that rule would require keeping everyone out, even those strolling through on their way home, Focht said.
James Foster and John Brown, two homeless men who live in the park, said they clean up after themselves. As they played cards with a deck from Harrah's, they pointed to a broom they keep nearby. Figlestahler confirmed that they help.
Foster and Brown said they think younger people are more responsible for dirtying the park than homeless people are.
"The kids see the trash cans and throw stuff on the ground anyway and keep moving," Foster said.
The collection of litter contributes to the odd carnival. On Tuesday, a naked Barbie doll lay face down on a grate on the south side of the park, while on the west side, someone had plastered a sticker that read "Krack Killz" on a sign in one of the planting beds.
LOVE Park's design contributes to the challenges of maintaining it. Its flat surfaces and ledges lure skateboarders, who even pulled a granite block halfway out of its lodgings to create a small jumping ramp. The park's high walls and multiple levels and corners create havens for litter.
"There are a lot of hiding places," Figlestahler said.
A renovation of the park is finally in the pipeline, with completion scheduled by 2015. The project was originally budgeted at $20 million but was recently scaled back to $15 million by City Council.
To comply with the Americans With Disabilities Act, the new design must be flatter and more accessible from the street, which should make it easier to maintain, Focht said.
Until that happens, Figlestahler is the park's Sisyphus, tidying up, going home, and arriving the next day to sweep up again.
He pays special attention to the area around the LOVE sculpture, knowing that tourists will remember if it looks dirty.
He is not required to clean up excrement, but he does it anyway.
"It's not really my job," he said, "but I do it out of respect for the people in the park."
When he sees children playing in the fountain, Figlestahler tells their parents to watch for broken glass.
"He's just the kindest, gentlest soul, and he does an extraordinary job under extremely difficult circumstances," Focht said.
Most mornings, Figlestahler fills about a dozen large commercial bags with LOVE Park trash. He says he enjoys caring for the city's outdoor space.
"It's a beautiful park," he said. "It just gets heavily used."
With that, he headed off to fish plastic soda bottles out of the fountain.
Contact Miriam Hill at 215-854-5520, firstname.lastname@example.org or @miriamhill on Twitter.