On a picturesque spring day, dozens of Washingtonians gather in Dupont Circle, the grassy spot in the center of a D.C. neighborhood know for its cafes, galleries and boutiques. Few are likely to know what lies beneath them: more than 75,000 square feet of tunnels that haven’t been open to the public in 15 years.

To access them isn’t simple: The only way the public gets there is through a tour led by the Arts Coalition for the Dupont Underground, which has permission from the city to lead groups to the site it hopes to redevelop. And the only pathway to enter those tunnels is by walking down a narrow underpass where cars and buses whiz perilously close by. Upon entering the tunnels through a nondescript door, visitors are greeted by a cloud of darkness and stale musk. Welcome to the Dupont Underground.

The tunnels – which run N Street to S Street – originally served the city’s streetcar system from about 1949 to 1962. Since then, the tunnels have been virtually unused, save for a short-live food court called Dupont Down Under that opened in 1995 and failed spectacularly, closing the following year. Today, on a tour led by flashlight, visitors see little more than graffiti, signs indicating station exits, and rail tracks that haven't been used in a half-century.
But members of the non-profit Dupont Underground view the tunnels as an opportunity for the city and hope to re-develop the space into something truly unique. They see wineries, cafes, bookstores, art galleries, pop-up retail and an events space where dank corridors currently stand. The project is the brainchild of Julian Hunt, an architect who has been fascinated by the space and envisioned big possibilities for it ever since he moved from Barcelona to Washington in 1995.  Hunt and his colleagues draw parallels between their efforts and New York’s High Line – a grassroots redevelopment effort that snowballed to become a major success story for the city. 
In 2010, Hunt’s nonprofit responded to a request for proposals from the city and won exclusive rights to the corridors. They don't have a lease, but the deal ensures that, at least for now, his nonprofit is the go-to group when it comes to figuring out what to do with the site. The deal also gives Dupont Underground access to the tunnels, which it uses to take Washingtonians on tours in an effort to quietly drum up support. Restoring the site to a basic, usable condition – with little more amenities than bathrooms and ventilation – would cost $30 million. The group is soliciting philanthropic contributions and trying to land developers.
But the non-profit faces obstacles. Its deal with the city was struck in 2010, but since then, a new administration has come to city hall that inherited an undertaking it didn’t launch. At this point, members of the non-profit say, the city is largely hands-off. (A spokesman for the city’s Office of the Deputy Mayor for Planning and Economic Development didn’t respond to several requests for comment). "We need to start changing the city's mind about how this can work," says Braulio Agnese, managing director of the nonprofit.
Then there’s a matter of convincing a developer of the site. Despite being unique – and somewhat beautiful in a strange way – the long, narrow corridors pose some logistical challenges, and most developers won't have experience working on a project like this. Hunt says while there are some underground redevelopments in other parts of the world, he has yet to find any in the U.S. "It's unlike anything most people have seen,” says Agnese.
The non-profit may also have to battle resistance from preservationists, as their plan would require re-locating a small, historic building. And even if they get the go-ahead from the city, they’ll still need federal approval, since Dupont Circle and several surrounding plots of land are under the jurisdiction of the National Parks Service.
Still, despite the long road ahead, Dupont Underground sees a light at the end of the tunnel. “This city is changing,” says Agnese. “It’s having an identity beyond the federal government. We’re seeing this as something that can help that.”