Weirdly hip.

In these sweet, waning days of August, a line forms out the door and around the corner at the retro spot, and the tables, set in the shade of a cypress, are filled. Women in thigh-high dresses, men with pierced ears, shaved-headed doctors in scrubs, and sockless bankers in tasseled loafers.

What are they doing here?

"The ice cream's the best, and I love the old-fashioned theme that's going on," explains Chip Mattson, 45, from Chestnut Hill, whose nice tan is set off by his pink oxford shirt. He's in the advertising business, and considers himself "an ice-cream head."

Ryan Berley, at 32 the elder of the two emporium owners, saunters up. His hair is parted in the middle and slicked down, he wears a real bow tie, a white shirt, suspenders, and high-waisted trousers. Thanking Mattson for patronizing his establishment, he asks, "If you don't mind, what flavor did you order?"

"Peanut butter and coffee."

"Good combination!"

"Yes, it is."

"My own favorite thing is a vanilla milk shake," Berley says. "Plain and classic."

Figures.

Four years ago, Ryan and Eric Berley lived pretty much like any other fairly normal 21st-century men. They grew up in Media and went to college, and after their parents bought the building on the site of a former erotic-cake bakery, they decided to turn it into a circa-1904 ice cream parlor.

While time and the rest of the neighborhood moved forward - with sushi restaurants and multimedia art galleries and martini bars - the Berley boys flipped into reverse.

"The longer we're in this, the more it's a lifestyle," Ryan Berley says. They went to a Phillies game last week and were stumped about how to dress for the occasion. "What are people wearing these days?"

"We're living this completely," his brother says, taking off his straw boater and smoothing his hair. (He admits, however, on this, the morning after his 28th birthday celebration at a bar in South Philly, that he's nursing a bout of 21st-century sleep deprivation.)

Business has tripled since they opened in September 2004, they say. They now make all their own ice cream in Northern Liberties above Honey's restaurant, and at the height of the season - now - they produce 400 gallons a week.

Doing his part, Steve Goldstein, a surgeon at Pennsylvania Hospital, has ordered a Mount Vesuvius - a colossal warm brownie and hot-fudge sundae topped with whipped cream and malt powder.

"It's called dinner," says Goldstein, who has just left work after finishing a revision rhinoplasty - that is, a do-over nose job.

Across the table, lawyer Mark Epstein, 37, has bought a scoop of vanilla for his white toy poodles, Marlowe and Oliver, who look like mounds of whipped cream as they lap it up.

"Here," says his wife. "Daddy will hold it for you!"

Another lawyer, Jesse Silverman, sits down in his pinstripe suit, places his briefcase on a chair, and attacks a cherry bomb - a long, tall glass of cherry soda with chocolate ice cream.

"I don't really like the movement we're seeing today toward exotic ice cream flavors," Silverman says. "I hearken back to a time when the only flavors were strawberry, chocolate and vanilla."

He says he's been coming here for many years. Except it's been open for only four.

"Ah," he says. "But it seems so much older."

Around the corner, Rob Formica, 29, of Mount Airy, and his wife, Shoshanna, are sharing a sundae.

"It makes it more romantic," she says.

"Plus," he says, "they'd have to roll us out on carts if we each had our own."

The Berleys used to close for winter. No more, though. In a country that annually consumes about $14 billion worth of ice cream desserts away from home, there's enough business to keep them going straight through.

The new pastry chef's brownies help. "They've got a lot of butter," Eric Berley says. "Butter and eggs. An enormous amount of butter."

Shoshanna Formica recently discovered that she and Ryan Berley went to high school together. "I don't remember him," she says. Never mind. She is proud to have almost known him and his brother.

"I love how they found authentic everything," she says. "It's so uniquely Philadelphia. And I like supporting small businesses, since I have one myself." (She's a photographer.)

The couple are almost celebrating their first anniversary, which arrives next week. And for the occasion, her husband, it turns out, has made a sacrifice with Vesuvius.

It's not his favorite. Especially with 34 days before the first day of fall.

"Nothing says summer," he says, "like blackberry and peach ice cream."