What if someone built a national park next to one of the largest U.S. cities and hardly anyone came?

That seems to be the case with Oxon Cove Park, a 500-acre gem that is just 2 miles south of Washington, DC and just one exit off the busy Capital Beltway. It offers a variety of plants along hiking and biking trails, a woodsy area for fishing and historic buildings that date back more than 200 years. The property’s Oxon Hill Farm includes 70 acres and an opportunity to see goats, chickens and a donkey.

Nearly 6 million people live within a short drive of the park; more than a million could walk or bike there. Yet, just 30,000 visitors a year discover the park, and most of them come on school field trips from Prince George’s County, MD, the District of Columbia and Alexandria, VA.

The staff at Oxon Cove is trying to reach out to its neighbors and remind them that the park is here. But that job is getting harder — even as both the public and government agencies are seeing more value in urban parks and wildlife refuges.

Recent construction at nearby National Harbor has rerouted traffic in such a way that many motorists miss the park’s wooden sign. Entering requires a convoluted left off one highway crossing many lanes of traffic on another. With the entrance poorly marked, many visitors who seek the park end up making U-turns on Oxon Hill Road or Indian Head Highway.

“We’re trying to figure out which authority to talk to so we can actually get an address,” said Adam Gresek, supervisor for Oxon Cove Park.

The development of the National Harbor complex nearby has fueled speculation that the park is in jeopardy. Just above Oxon Cove’s serene, moss-covered trails, cranes dot the sky, finishing a $1 billion casino that will be a centerpiece at National Harbor. Already, a bustling outlet center rises on one side of the park. On the other is Blue Plains, one of the largest sewage treatment plants in the world. Atmospheric it is not.

Oxon Cove “is the poster child of underfunded, resourced parks,” said Ed Stierli, field representative at the National Parks Conservation Association. “A lot of people think that because it is preserved, it’s preserved in perpetuity. But that is not the case.”

It would take an act of Congress to siphon off a piece of a national park and, say, add it to a burgeoning casino development. But that doesn’t mean it wouldn’t happen. Over the last three decades, both the federal government and local developers have hatched plans to turn part of the park into a women’s prison, a golf course and housing. None of those plans came to fruition.

Last year, the town of Forest Heights annexed the park, fueling worries that it could become commercialized. Forest Heights Mayor Jacqueline Goodall said the town has no plans to develop the park, only plans to improve it. Oxon Run, a tidal stream that deposits into the Potomac, has long been impaired because of stormwater runoff, trash and other pollutants. The town, she said, simply annexed the land to connect the town to its publicly owned spaces so it can make better planning decisions. It has no plans to develop the land, but does want to improve access.

At Oxon Cove Park and Oxon Hill Farm, visitors can look over the Potomac and imagine the view that Mary DeButts’ family witnessed from her farmhouse on the property during the War of 1812. Washington, DC, was burning, and the British would soon make their way toward Baltimore, where they would underestimate the might of the port city and lose a battle that helped end the war.

“I cannot express to you the distress it has occasioned at the Battle of Bladensburg. We heard every fire. Our house was shook repeatedly by the firing upon forts and bridges, and illuminated by the fires in our Capital,” Mary DeButts wrote to her sister, Millicent, in 1815.

Oxon Cove remained a working farm until the DeButts family sold the property to the U.S. government so it could establish a therapeutic farm there. The farm, called Godding Croft, was part of St. Elizabeth’s hospital. Doctors hoped that being outside and among the animals would be therapeutic for the mentally ill patients, many of them members of the military. In 1959, the National Park Service acquired the property with a mandate to protect it from development. Activities at the park include living history enactments; tours of the historic plantation home, Mount Welby; and birding walks.

“It’s a little agricultural gem surrounded by urban,” said Paula Becker of the Maryland Department of Natural Resources.

But park users say they have noticed neglect over the years. Jim Hudnall, the public affairs chairman for the Oxon Hill Biking Association, once commuted along the park’s bike trail to work at the U.S. Naval Research Laboratory just north of the cove. Today, he said, commuters prefer to take the bike lanes over the Woodrow Wilson Bridge and connect to DC through Alexandria.

Three decades ago, Hudnall said, he saw fishermen lining the cove and eating their catch. These days, signs warn anglers not to consume any fish because of recent sewage spills. The park schedules regular cleanups, but staff said they generally only attract a handful of volunteers.

On a late fall day, Oxon Cove was looking worse for the wear. The farm part of the park was well-kept, and children were enjoying the animals. But down by the water, litter clogged the cove. At least 17 shopping carts littered the ground. It was not a pleasant place to walk, and indeed, not many people were there enjoying the unseasonable warm day.

The light foot and bike traffic at Oxon Cove is out of step with attendance at other DC parks. Millions of visitors arrive each year to see the monuments on the National Mall. And beyond that, DC is a city of outdoor enthusiasts. They jog through Rock Creek Park and climb the bluffs along Great Falls.

But those who love the park see potential beyond what it is. Don Briggs, superintendent for the National Park Service’s Potomac Heritage National Scenic Trail, envisions Oxon Cove Park as a connector between the bike trails along the Anacostia and Potomac, which could take cyclists from DC all the way to Harper’s Ferry.

Oxon Cove Park, Briggs said, could serve as a trailhead for multiple routes; it has parking, bathrooms and activities for children.

Nationwide, urban areas are embracing the wildlife around them. In 2013, the U.S. Fish and Wildlife Service named 10 urban wildlife refuges. The goal of the initiative is to bring the 80 percent of the population that lives in urban areas closer to nature and, in the process, clean up some previously neglected areas. One such area is Masonville Cove, about 60 miles north of Oxon Cove on the industrial fringes of Baltimore. Once a dump for tires, broken-down ships and even debris from the Great Baltimore Fire of 1904, the cove is now home to turtles, geese, water snakes and acres of restored wetlands.

The cove’s staff is working to improve bus routes so more visitors can participate in the programs. But like Oxon Cove, Masonville struggles to bring in visitors that are not coming as part of a program. Masonville is also a little hard to find — off Interstate 895, and close to I-695, I-95 and Hanover Street. It is also just a few miles from downtown, and yet, somehow, hidden.

Oxon Cove’s dedicated staff is hoping that National Harbor will eventually draw people to the park — and engender new love for it.

“I have faith that the Park Service is going to hang on to this property because it is valuable,” said Stephanie Marrone, a ranger. “And the more developed the area is getting, the more valuable this place becomes.”

A version of this story appeared in the National Parks Conservation Association magazine.