Boston Sand and Gravel, now in its 102d year of operation, is one of the city’s most curious landmarks. With its giant cisterns towering 120 feet in the air and its long double-barrel conveyor belts angling earthward, the concrete mixing plant looks more like it belongs as the backdrop for a scene in a Batman movie. Indeed, it’s been used by Hollywood for “The Departed,’’ “The Town,’’ and “The Equalizer.’’

But why is a hulking concrete plant, enmeshed in a spider web of highways and onramps, sitting in the middle of prime real estate? Just 1,200 feet away, in North Point, newly constructed luxury housing units are renting for $3,200 per month for a one-bedroom.

The question has come up on Reddit, which asked “What’s the story behind Boston sand and gravel?’’ Dozens of comments in response range from the ridiculous: “[Ben] Affleck has a part time gig down there’’ to the logical: “Why would you want to move the city’s largest concrete supplier further from the city?’’

But whether it remains a concrete plant or is sold for new construction, its most valuable contribution to the region may have more to do with 43 miles of rail in New Hampshire that the company fortuitously thought to purchase in 1986.

Boston Sand and Gravel first opened at the current site of the Cambridgeside Galleria. At the time, the best method to extract raw materials for concrete was to dredge the ocean floor. The sand and gravel came in by boat via aqueduct. Soon, however, technology and resources necessitated a move to the rails. That’s why the current operation sits near tracks owned by the MBTA. Today, sand and gravel come in on rail from a pit 100 miles north, in Ossipee, N.H.

It’s that stretch of rail, rather than the plant itself, that has captured imaginations.

“We have a crisis in New England where the major tourist destinations are not accessible by public transportation,’’ said Peter J. Griffin, president of the New Hampshire Railroad Revitalization Association, a group trying to bring back rail across the region.

He wants to see a return of the old ski train route that would bring riders to North Conway — a popular destination for skiers, hikers, and other year-round tourists.

Today, a freight train can go from Boston only as far as Ossipee. To get to North Conway, 25 miles away, the rail lines would have to be upgraded for passenger service. A 2004 study by New Hampshire’s Department of Transportation estimated the cost for that portion alone to be $6 million.

Those familiar with New Hampshire’s recent forays into passenger rail are probably rolling their eyes right now. New Hampshire rail once had 24 points of access to neighboring states and Canada. Today it has four.

In 2015, the New Hampshire Legislature foolishly rejected even studying the plans for the Capitol Corridor, which would bring passenger service from Boston to Manchester. The plan called for more than $70 million in outside investment, including funds from Massachusetts.

In response to the Legislature’s short-sightedness, New Hampshire transportation officials have turned their attention to public-private partnerships, recently releasing a request for proposals to make use of defunct rail corridors, including the former ski train route. According to Patrick C. Herlihy from the Department of Transportation, there is interest from private companies looking to invest in the upgrade of existing rail corridors for passenger and commercial service.

One of those companies, Golden Eagle Railway, has plans to run a luxury train, with a four-star restaurant onboard, from Boston to Montreal, with stops along the way at the Mount Washington Hotel and other popular destinations. According to its president, David Schwanke, the company has already had conversations with the various owners of the track, including Boston Sand and Gravel. He believes he can fund the entire project — which would cost hundreds of millions of dollars — with private investment. He claims he could have service running as soon as next year if the state moves forward quickly with awarding a lease to the selected proposal.

More than the stalled Capitol Corridor, it’s this private-public partnership that has the best shot to connect the North Country, Schwanke says.

For decades, sand and gravel have been carted down the old rails from New Hampshire to Boston. And those raw materials built — and are still building — many of the city’s roads and buildings. For the first time in many years, Boston’s best shot at building a passenger rail corridor to New Hampshire now runs down those same tracks.

Mike Ross writes regularly for the Globe. Follow him on Twitter @MikeForBoston.