ORLANDO, Fla. — It took 30 minutes of wandering, but Jamie Giffin and her group of friends finally found the unmarked elevator door that serves as the entrance to Pharmacy restaurant.

“We had heard about Pharmacy around town, but we could barely find anything on the Internet about it,” Giffin said. “All they had was a strange website, and the address was hidden at the very bottom behind an elevator door.”

Pharmacy’s hidden location and ambiguous name are no coincidence. Across Orlando there are a growing number of hidden establishments operating via secret doors and passwords. The businesses hark back to 1920s speakeasies, when Prohibition forced many establishments to keep their existence secret.

But these days, owners hope the clandestine nature will create buzz and appeal that can’t be gained through advertising.

For Giffin, the difficulty of finding Pharmacy only added to the allure of the carefully hidden culinary mystery. Giffin, who closely follows local restaurants, said she heard about Pharmacy through a group of friends and liked the appeal of a tucked-away secret.

The “secret door” trend didn’t originate in Orlando, and the approach has been developed in bigger cities such as New York and Chicago in recent years. But a wave of 1920s nostalgia and a surge in popularity of craft cocktails has brought new life to speakeasy-style places.

“We’re fun, and we’re whimsical,” said Pharmacy co-owner Tyler Brassil. “We play up the speakeasy aspect, and people really seem to like it. We get people dressing up in 1920s clothing and doing the whole speakeasy thing all the time.”

The social-media age and the shift away from mainstream-restaurant concepts have made the secret-restaurant-and-bar concept possible, said Michael “Doc” Terry, a restaurant-management expert and instructor at the University of Central Florida’s Rosen College of Hospitality Management.

“We’ve already seen it at places like In-N-Out Burger with a secret menu,” Terry said. “It’s just one more way to make customers feel like they are special, like they found something that no one else did.”

Secret-door establishments such as Pharmacy usually don’t keep their existence completely hidden.

Many operate websites and Facebook pages, even displaying pictures of recent events. Pharmacy is busy even on weeknights, and there are often long wait times on weekends.

Operating a restaurant with no advertising or even exterior signs can be a dangerous endeavor, Terry said.

“You have to reach out to the trendsetters and hope they catch on,” Terry said.

Another deceptively named business, Hanson’s Shoe Repair, is a cocktail bar in downtown Orlando. The only way to gain entrance is by calling a phone number and following the directions on a scratchy recording. Callers receive reservations through a call back that gives a password to enter the bar.

Though Pharmacy and Hanson’s follow the Roaring ’20s vibe, the secret door isn’t reserved only for retro-style establishments.

There is a “speakeasy” for comic-book nerds called “Geek Easy” inside A Comic Shop in Orlando. Geek Easy is a hidden bar for fans of comic books, fantasy and science fiction that hosts events and games. The Geek Easy does serve food and alcohol as well.

Downtown Orlando hookah bar Kush Ultralounge is just above tobacco shop Kathmandu. Visitors to Kush are granted access by asking the shopkeeper at Kathmandu for the secret-door code located inside the shop.

“The secret thing is kind of a double-edged sword,” said Matt Taylor, the manager at Kush. “We don’t advertise at all, so word of mouth has to bring everyone in.”

The space that now houses Pharmacy is next door to The Table, Brassil’s first restaurant.

Brassil and his partners wanted to open another restaurant next door, but there were no windows in the vacant space. They took the windowless space as a challenge and added a nondescript elevator door as an entrance to make Pharmacy just a bit harder to find.

Because Brassil and his wife, Loren Falsone, are accomplished chefs in their own right, creating awareness for the Pharmacy wasn’t difficult.

“There were people waiting to get in the first night,” said Brassil, who noted that his restaurant doesn’t accept reservations. “And I still sometimes see people wandering around late at night, and they are clearly looking for Pharmacy.”