When Ryan Gravel was a student of architecture and urban planning at Georgia Tech in the late 1990s, he came up with an idea to transform Atlanta’s system of abandoned railroads into a greenway that would create much-needed public space. “I never imagined we would build it one day,” he says. “I just wanted to graduate.”

Today, the Atlanta BeltLine, born from Gravel’s idea, is poised to reclaim more than a thousand unused acres from a ring of railroads built around Atlanta after the Civil War, long neglected since cars became the preferred method of transport. “I wanted to reuse them as a transit loop to revitalize the adjacent communities and incentivize the growth of the land along the way,” Gravel says. His plan, which gained the support of the city through a grassroots campaign initiated in 2001, will convert the 22-mile belt into trails, transit, and parks. While construction may not be completed until 2031, a handful of refreshed parks and the two-mile Eastside Trail have become popular destinations since opening in 2011 and 2012, respectively.

Gravel hopes the BeltLine will unite disconnected communities. “In Atlanta we mostly drive in our cars, and we don’t look each other in the eye when we do that,” he says. “The physical barriers of the city are now being turned into a meeting ground.”