A top tourist activity is Boston’s Freedom Trail — marked by a red line on the pavement through downtown Boston — that takes people to a collection of museums, burying grounds and historic markers that tell the story of the American Revolution.

But over the last 300 years, Boston also has served as a hub of scientific innovation. To honor this history, a new walking tour launched last month called the Innovation Trail. It’s the brainchild of Boston Globe correspondent Scott Kirsner. The tour highlights 21 major breakthroughs in science, medicine and technology that happened in Boston and Cambridge, including the invention of the telephone, anesthesia and life-changing biotech drugs.

Boston is a perfect place for a tour that mixes history with science, said Kirsner. “It combines this love of history, this love of storytelling. But also this love of the future and discovery, figuring out what’s next,” he said.

Kirsner had written a few columns on historic places in Boston where the telephone was invented, or where Bill Gates decided to start Microsoft. But he wanted to piece all these places together. The Innovation Trail does just that.

People can do a self-guided tour of the trail using a map on their website. There are also guided tours scheduled Friday through Sunday for the Kendall Square portion of the trail. The tour starts in Downtown Crossing and goes to Kendall Square, ending near Toscanini’s ice cream.

“We wanted to make it walkable,” Kirsner told Boston Public Radio on Monday. Near Toscanini’s is the last remaining candy factory in Cambridge, a city which used to be a manufacturing powerhouse, but is now known more for its hip restaurants and college students.

“One of the last industrial things they’re doing is making Junior Mints, Sugar Babies and Sugar Daddies in that factory still on Main St.,” said Kirsner.

The trail serves as a reminder of the advances that now seem commonplace: the telephone, anesthesia, organ transplants, color film and more recently, the first COVID-19 vaccines. One of the final stops in Cambridge is the Moderna building where the first modified RNA vaccines for the coronavirus were created.

Also on the Cambridge side is the Broad Discovery Center, one of four museums featured on the tour. “You have four science museums within walking distance of each other which is really exciting,” said Namrata Sengupta, the associate director of scientific public engagement at the museum. The Broad Discovery Center tells the story of how scientists in Greater Boston are working to develop better diagnostics and treatments for human disease, from cancer to infection.

Sengupta sees the Innovation Trail as a way to translate science happening everyday in Greater Boston to the many visitors coming through the area. It also shows young people working and living in Boston that they belong in the innovation and technology community.

“It’s our responsibility who are part of organizations like this to make young people … feel like they belong in this ecosystem,” Sengupta said. “Storytelling has a huge power.”

In recent columns, Kirsner has called on leaders and business to retell the “narrative” of Massachusetts to get young people to stay after college and get businesses to invest. He said the Innovation Trail is part of that storytelling. And it’s not just the private or public sector that needs to change the narrative, said Kirsner. “It’s everybody who lives here. There’s a lot to be proud of in Boston, Cambridge and this state as a whole.”