It's piled with caramelized onions, smoked Gouda, bacon, pickled long-hots and chili-mayo.
Bartender Keith Hayman says there's just something special about it.
"The love, the magic, I don't know exactly. People love the burger though," Hayman said.
Royal Tavern got a shout out in the September issue of Esquire.
The magazine named Philadelphia "the Late Night Capital of the US" when it comes to food and fun.
No surprise to Meryl Levitz, the CEO of the Greater Philadelphia Tourism Marketing Corporation.
"Philly, in the last 20 years, has become an overnight sensation," Levitz said.
Her non-profit has been working for years to push Philly as an overnight destination, not just a daytrip.
"Philadelphia at some point decided the day was not going to fold up at 5:00 p.m.," Levitz said.
For locals and out-of-towners alike that night could very well include a cheesesteak.
Hot steak sizzles on the grill at Tony Luke's in South Philadelphia. A popular post-game spot, patrons know no matter the hour, their food will be hot and fresh.
"We cook them on 225 and they slow cook. So you may have to wait a little longer, but you'll get a good sandwich," Darryl Thomas of Tony Luke's said.
One Chinatown restaurant also got an Esquire mention, but some say the late-night food picks are endless and you can't go wrong.
"It's the best place. You really can get what you want," Chinatown resident Victor Zhang said.
Whatever the dish, the new title is no shock to lifelong Philadelphians we spoke with, but some New Yorkers registered a rebuttal.
"I just think New York has a lot more to do at night," Daniella Zandi said.
"It's the type of city where if you need anything at any given hour you don't have to walk more than three or four blocks to get it," David Zandi said.
For a lot of people we spoke to the recognition for food and fun in this city is long deserved. And the great news is, the restaurants featured in the article are just the tip of one very delicious iceberg.