Richard and Barbara Tiplady bought 16 acres of woods along the Potomac River in Dumfries in 1987 because it reminded them of Flirtation Walk, a pedestrian path for cadets at West Point where they had gone on their first few dates.

Richard was a cadet; Barbara was a member of the Women's Army Corps.

The couple paid $30,000 for the property, with its picturesque view of the Potomac and the Charles County shoreline. But their lover's lane with a great view has turned into much more.

They literally stumbled upon the Cockpit Point Battery, a fort that was part of the Confederate Army's blockade of the river from 1861 to 1862. After negotiations and assurances that the fort would be preserved, the Tipladys sold the historical land in September for about $1.2 million to Vienna-based developer KSI Services.

KSI and Prince William County are now negotiating a plan to preserve the fort and make it open to the public.

"When you develop in a community, you look for things you can do," said Edward S. Byrne, senior vice president at KSI, which is building Harbor Station -- a luxury hotel and conference center with a Jack Nicklaus-designed golf course -- at the site. "It's usually giving money for schools or transportation. When we looked around, people said, 'You know, there's this property with historical significance.' "

Preserving the Cockpit Point Battery is part of Prince William's efforts to salvage what's left of its past. Known for decades as the place for inexpensive townhouses and outlet shopping, the county has tried to become more culturally and historically aware, particularly of its role in the Civil War.

In May, the county was named a Preserve America community under a White House initiative that recognizes cities and counties for maintaining cultural heritage. Prince William hired Brendon Hanafin as its first historical preservation manager about three years ago. He is overseeing the restoration of Ben Lomond Manor House, which served as a hospital during the Civil War, and Rippon Lodge, Prince William's oldest house, which the county bought for $1.4 million and plans to turn into a museum.

Hanafin's division has several other properties under its care, including two historical courthouses. He and his staff are working with other developers on preserving Bristoe Station, the site of another significant Civil War battle, and the Lucasville School for Colored Children, a little red schoolhouse that opened in 1884.

Cockpit Point is in an area known as Possum Nose, nestled 70 feet up a cliff facing the Potomac. Hanafin, Byrne and a posse of explorers walked the grounds last week. Hanafin stopped and bounced on a pile of leaves. "It's spongy right here," he said, explaining that a hole beneath the leaves probably housed the makeshift fireplace of an officer's hut.

Historian Mary Alice Wills, who wrote "The Confederate Blockade of Washington, D.C., 1861-1862," said the Confederates "effectively closed the Potomac to imports into Washington, D.C."

The Union was thus forced to use Baltimore waterways, said Wills, who teaches at Houston Community College in Texas. The blockade was not well documented at the time because the Union was embarrassed by the blockade's effectiveness and the Confederates did not want the Union to know its strategy.

Although Prince William was interested in adding the Tipladys' property to its growing collection of historical sites, the price was out of reach, said Sean T. Connaughton (R), chairman of the Board of County Supervisors. The county believed $100,000 was a good offer, Connaughton said. The land was assessed at $139,300 in January 2004, according to county property records.

KSI also thought the nearly $1.2 million price tag was a bit much but was willing to pay it as a public service, Byrne said.

Richard Tiplady would not discuss details of the sale. "You can refer to the public record," he said.

But he was giddy about the historical discovery.

The Tipladys, married for 41 years, moved to Dumfries in 1972 and worked mostly at the Pentagon. They bought a home on the Potomac in the small town, but Barbara Tiplady said she had dreams of building a house on Possum Nose that would serve as a daily reminder of ambling with her husband on Flirtation Walk, made famous by the 1934 Oscar-nominated film of the same name.

After buying the property in 1987, the Tipladys took their strolls in the woods, listening to the crunching leaves beneath their feet, and they often fell into holes and saw what appeared to be trenches, they said. "I'm a little embarrassed. I expected a little more from myself as a West Point graduate," Richard Tiplady, 65, said. "I wasn't really sure about those holes."

It was their visiting friends, also graduates of West Point, who told them that it was probably a military fortification, he said. More research led to stronger conclusions that those holes were the breastworks of the Confederate Army. The fort's remote location and oak trees slowed erosion and helped preserve it, Hanafin said.

The property can be reached only from the Potomac or by driving along railroad tracks on a rock road and walking up steep trails. Last week, a few beer bottles and soda cans showed that some people probably have made the trek, but deeper into the woods, the terrain appears undisturbed.

Although the Tipladys knew the fort's historical significance for several years, they tried to keep it quiet and declined an offer for the site to be placed on the National Register of Historic Places. They allowed select tourists to travel the trails but feared that Civil War buffs would flood the area, Richard Tiplady said.

He said that they had found evidence of digging, possibly by scavengers searching for relics, and that they could not afford to fence the property.

Along came KSI a couple of years ago, and the Tipladys decided to turn over the site. The deed transferring the property reads: "Civil War gun emplacements and connecting breastworks on property herein . . . shall be preserved and safeguarded against all disturbing activity."

"Those are mine and Barbara's words," Richard Tiplady said. "We're just thrilled that they are going to make it a park."

Prince William employee Jane Beyer and KSI project manager Brian English look out over Cockpit Point Battery. KSI, which plans to build a hotel, conference center and golf course in that area, is in talks with the county on making the fort open to the public.