Longtime viewers of the “Law & Order” franchise know a diner is an integral part of the history: a safe haven for the detectives to grab a bite between cases or question potential witnesses of a crime.

And now, fans can visit the “Dun Dun Diner,” a special pop-up celebrating 25 years of the mothership series. Don’t worry, “SVU” lovers, there are nods to Olivia Benson and Elliot Stabler, as well.

The attraction, from NBC and Peacock in collaboration with NVE Experience Agency, will run from Friday, Oct. 3, to Sunday, Oct. 5, at New York City’s Rockefeller Center. Reservations were free and available to the public on a first-come, first-served basis. While reservations are sold out, the retro diner set is visible to all from the outside and makes for a cool photo-op.

Read on to learn about what to expect from the “Dun Dun Diner.”

Entering the ‘Dun Dun Diner’

Within seconds of walking into the diner, a charismatic host greets patrons and presents a menu with food and merchandise options.

“Dun Dun Diner has been proudly serving Dedicated Detectives since 1990,” the menu reads, along with a list of clever food options like Fin’s French Toast, Partner Parfait and coffee “from our friends at Benson & Co.”

That message mirrors one on a wall behind two suits worn by two of the franchise’s most famous actors: Jerry Orbach, who played Detective Lennie Briscoe, and Jesse L. Martin, who played Briscoe’s partner Detective Ed Green.

Then attendees line up for a photo at a red diner booth with a backdrop decorated in honor of Mariska Hargitay’s Capt. Olivia Benson. A neon “What Would Olivia Benson Do?” sign flashes proudly in the middle of photos of her iconic character and a green sign from Olivia Benson Plaza, which was a similar “L&O” fan experience at 30 Rock.

After snapping three photos, fans place food and coffee orders at the counter before surveying some merch.

‘Dun Dun Diner’ Merchandise

The limited-edition merchandise is on display in a case similar to one used for dessert spreads in a diner.

Some free swag is included in the visit, and dinergoers can choose from one of three hats to get in a reusable “Elite Squad”-branded to-go bag. A keepsake diner mug is also included.

A half-zip sweatshirt and T-shirt/sock bundle from Dinner Service NY are also for sale at another counter.

For those undecided detectives, there’s a QR code available to scan to order the items online. Additionally, a dark T-shirt with Olivia Benson and the words “Still New York’s Finest” is available for preorder through another QR code and also on the NBCUniversal Shop’s website.

Taking a Seat at the ‘Dun Dun Diner’

A hostess helps seat patrons after they grab a copy of the Law & Order Ledger to read at a table, which is decked out with interactive place mats. The mats are filled with trivia questions, word scrambles and one of Benson’s recent diner-related quotes to Stabler: “Detective, you feeling hangry?”

The walls of the dining room are also covered in “Law & Order” photos of past and present cast members and famous guest stars, like Jeremy Allen White, Ludacris and Serena Williams.

Another area features a snuggled-up snap of Benson and Stabler next to a plate with a Season 1 Stabler quote, “I’m your partner for better or worse.”

After indulging in coffee and food, guests get a check with a message signed by “L&O” creator Dick Wolf.

No trip to the diner is complete without a sweet treat! Fans receive a free cookie from Milk Bar on their way out the door.