Tower 7, as it's known, is 65 years old and 110 feet tall, scratched with graffiti and whipped by decades of salty ocean winds - but it remains nearly as solid as the day it was hurriedly built by a country on the verge of war.
Horace Knowles is 84 and about 5-foot-10. He is still standing tall, too, despite circulatory problems and respiratory issues that force him to use a portable oxygen tank when he takes his memory-stirring walks through the dunes over which the tower looms.
Once, they - the tower and Knowles - shared a mission.
Knowles was one of about 2,000 soldiers dispatched - nearly a year before Pearl Harbor - to a barren stretch of beach near the mouth of the Delaware Bay to build a fort and man the heavy artillery that would protect America's shores from enemy attack.
Tower 7 is one of 11 curious concrete cylinders that rise from Delaware's coastline, from its southern edge in Fenwick Island to Cape Henlopen, all built to provide a vantage point from which the coordinates of enemy ships could be relayed to gunners, such as Knowles, stationed in nearby bunkers.
As it turned out, no enemy ships were ever fired upon. The low-profile oceanfront fort, as radar and weapons technology progressed, was obsolete even before World War II was over. And Knowles' unit, the 261st Coast Artillery, quietly went out of existence afterward, its work protecting America's coast rating only a paragraph or two, if that, in most history books.
What was known as Fort Miles all but disappeared when, in 1963, the federal government began turning the land over to Delaware's state park system.
Once the site of one of the heaviest concentrations of artillery on the East Coast, it became Cape Henlopen State Park, a place for vacationers to forget about their troubles and frolic in the sun.
Concrete block barracks became vacation cottages. What was once a gun battery became a bathhouse. The fort's brig became a nature center. And the wharf used to service mines laid in the Delaware Bay became a fishing pier.
As for the towers, they've endured far longer than anyone expected, including the Army Corps of Engineers, which predicted - because beach sand was used in mixing the concrete - they would only last about 20 years.
Instead, they've stood three times that long, most of that time idly, surviving freeze and thaw, careless tourists, and, in the case of the two towers across from Gordon's Pond in the state park, the ocean itself.
Although built nearly a quarter-mile from the shoreline, both now have waves lapping at them during high tide.
Mostly, for 40 years, they served to shelter sea birds and baffle beachgoers: Were they ugly lighthouses? Lifeguard stations? Silos for storing extra beach sand?
Tourists wondered, and while park employees did their best to explain, misconceptions spread.
"The younger generation is not well aware of what went on in these towers," Knowles said as he walked down a path in the state park. "And it's a damn shame."
Knowles, who after the war went on to a career with DuPont, the chemical company, takes walks in the park three times a week, clutching a bag that contains his portable oxygen, wearing a cap that says 261st Coast Artillery and - as skateboarders and bicyclists whiz by - recalling days when this swath of beach served a far different purpose.
Generally, his walks are undisturbed. But the other day, he said, a woman stopped him. "She said, 'You were stationed here, weren't you?' I said yes, and she thanked me. She said, 'Thanks for doing that.'"
Knowles paused to catch his breath. "There's not many people that thank us."
'A barren place' Horace Knowles was 19 when his Delaware National Guard unit was federalized in early 1941 and sent to Cape Henlopen for what they thought was a three-day training exercise.
On the third day, though, orders came to stay and build a fort on the land, which had been acquired by the War Department in 1938 as World War II loomed.
"It was just a barren place, no water or anything," said Knowles, who was in charge of putting up the tent city that - while quaintly referred to as "Camp Cranberry" by those who were building it - would evolve into a heavily fortified, $24 million Army base called Fort Miles.
Other than the patches of berries, it was far from paradise. There was no running water, and for the first year soldiers took baths out of their helmets. Foul odors wafted over regularly from a fish processing plant in Lewes. There were biting flies, cold winter nights and, until a dining hall was built, the constant crunch of sand in your food.
The fort was one of dozens that sprouted on U.S. soil in the prelude to World War II, many of them built to protect the estuaries that led to large port cities - in Fort Miles' case, oil refineries up the Delaware River, chemical plants in Wilmington and the Naval Shipyard in Philadelphia.
The fort, and its towers, were designed to defend the shores against Germany's surface fleet. But it never appeared. The far bigger problem turned out to be German submarines, which torpedoed hundreds of tankers and cargo ships along the Atlantic coast in the early months of the war, killing thousands of sailors.
Flotsam from the attacks would wash up on shore in beach towns like Lewes. Much of the beach was restricted and guarded by sentries. All of Kent and Sussex counties were required to engage in dim-out drills.
And around Fort Miles, residents had to put up with shattered windows and rattling china cabinets whenever target practice was under way.
"They would build targets and the tugs would pull the targets up and down the coast to see how accurate we were," Knowles said.
Shooting at moving targets miles away was a complex exercise, requiring readings from two adjacent towers, taken by soldiers using azimuth telescopes to peer through the slits in the tower walls. That information was radioed to a plotting room, where, through triangulation, the distance and speed of the targets would be determined. The coordinates would then be relayed to the gunners.
As wartime assignments went, though, it was low on glory; outside the immediate area, few even knew of the fort's existence.
Only once, Knowles said, did the gunners at Fort Miles fire at what they thought was an enemy. A passing ship had failed to acknowledge flash signals from the Navy and continued heading up into Delaware Bay. After a second warning shot, the ship halted and the crew was seen waving sheets on deck, Knowles said.
"The next day we found out it was an all-woman crew on a Polish ship that was coming here for supplies."
Knowles, though trained as a gunner, would sometimes pull duty in the towers. Usually, four men would be assigned at a time, scanning the ocean for enemy ships and aircraft, or passing the time playing cards.
Soldiers would also be called upon to patrol the coast on foot at night, watching for any Germans that might attempt to land on U.S. shores.
Fort Miles also became home to the 261st Coast Artillery, which lined the nearby waters with 500 mines. Had an enemy ship ever showed up - the only one that ever did was a German sub whose crew surrendered peacefully after hostilities had ceased - it wouldn't have gotten that far, Knowles insists; the gunners would have gotten it first.
"We were good," he said. "There's no getting around it. We were really good."
Restoration Horace Knowles stood in his old barracks - one of the few buildings at Fort Miles that still stands - and pointed to where his bunk once sat. "I know what it looks like in my mind," he said, "but I'd like to see it again."
He just might.
Sixty-five years after it went up, in an era when homeland security is back in vogue, parts of Fort Miles are being restored.
Last year, the fort and the towers within the state park were placed on the National Register of Historic Places; the rest of the towers, all on state land as well, are expected to receive similar status this year, said Lee Jennings, historian for the Delaware Division of Parks and Recreation.
This summer, work is under way on the first building to be renovated - returned to its 1940s appearance as part of a World War II museum that will depict the fort's role in history.
Plans call for a second tower to be restored and opened to the public. Tower 3, between Indian River Bay and Dewey Beach, will be equipped with the same range-finding equipment that was used during the war, and demonstrations will be given on how ships were spotted and targeted.
When the state first took over the towers, it considered demolishing some of them because of concerns about safety hazards and maintenance costs. Instead, most of them have been sealed and empty since the 1980s.
"The state has received many queries about them - from people who wanted to live in them or buy them," Jennings said.
"One of the biggest myths is that they were 'submarine towers,'" said Gary D. Wray, founder and president of the Fort Miles Historical Association and, who, with Jennings, co-authored Images of America, Fort Miles, a book released this year. "I've had people stand there and argue with me about it. When you stop and think about it, how is anyone going to see a submerged submarine from 80 feet up in a tower?"
A plaque describing the mission of the towers was placed alongside one of them a few years ago.
Knowles, meanwhile, who has been helping the state gather history about the old fort, says that, though he doubts he will live long enough to see it completed, the restoration is "the best thing that's happened in a long time."
"Fort Miles was essentially built by boys from Delaware, and Horace was one of them," said Wray, who teaches history at Wilmington College. "There are about 10 guys still around I know of, and they all get misty-eyed when they talk about their time at Fort Miles.
"They were young guys, proud of what they were doing. ... Now they're realizing they're not always going to be here. So if they can help preserve its memory, they want to."