“There’s an otherworldliness out there,’’ said Hollinger, who for 14 years has ferried other artists in his Boston Whaler to experience Fort Andrews. “Demolishing a building before its time extinguishes important historical stories. There’s nothing like the experience of walking through an abandoned town.’’

For all the possibilities, the demolition and landscaping will also tame an enchanting but dangerous ruin on New England’s maritime fringe. That saddens some Peddocks devotees, such as Steve Hollinger , a 48-year-old sculptor from Boston whose work has been inspired by the decay.

The campground will open this summer, when ferry service is set to resume, and advocates hope the island will become a recreation destination. There is no concrete plan, but Powers described potential in the remaining old buildings for a bed and breakfast or for corporate retreats. The parade ground could serve as a setting for festivals.

“Don’t distract yourself trying to save them all,’’ Powers said, “because you’ll never get anywhere.’’

Standing shin-deep in snow outside a rotting duplex on a recent morning, Tom Powers of the Boston Harbor Island Alliance recalled words of advice he received from an architect about preservation.

Some harbor advocates and history buffs had hoped to salvage the whole abandoned town. But securing a future for the essence of Peddocks meant facing up to what had to go.

Spearheaded by the island alliance and the state Department of Conservation and Recreation, the project originally targeted 14 buildings for demolition. A compromise with the Massachusetts Historical Commission and other preservationists lowered the number to 11. Crews will stabilize 11 other buildings to preserve them, while rehabilitating a white clapboard chapel, two guardhouses, and a stable.

To preserve what remains of the fort and prepare it for its next life — as a public campground and maybe much more — bulldozers will soon flatten almost half of the 26-building hamlet, including a derelict hospital and many of the dilapidated homes on a phantom street known as Officer’s Row. Demolition is expected to begin March 1.

Battalions of troops trained here for World War I. Thousands of Italian soldiers knew it as a prisoner of war camp during World War II that allowed weekend passes to the North End for home-cooked food and romance with local girls. It even functioned as a backdrop for Martin Scorsese’s 2010 film “Shutter Island.’’

Assailed by ocean wind and scavenged by vandals, this abandoned red-brick village was once Fort Andrews, a handsome century-old military complex with a rich history in a far corner of Boston Harbor.

Branches have sprouted from chimneys. Ovens in a boarded-up bakery have sat cold for decades. And thieves have stolen parts of the wood floor from the basketball court in the gymnasium.

But the romance of decline can go too far. Steps from the dock, the wooden roof of a three-story barracks has collapsed, an uneven red brick wall exposed like a jagged tooth on the edge of the parade ground. On the bluff that forms Officers’ Row, porches have flattened. At another house, a toilet sat alone on a pipe like a pedestal; the walls around it had crumbled.

“We preserve buildings so people can experience them,’’ said Sarah D. Kelly, executive director of the Boston Preservation Alliance, who signed the compromise. “Right now, the island is very alluring, and it’s fascinating to walk around. But it’s not in the state where you’d feel comfortable opening it up to large crowds of people. I think the goal is to retain some of that mystique and at the same time make the island more accessible.’’

The $7.8 million project will be funded with mitigation money from liquefied natural gas companies that laid an underwater pipeline and built other facilities around Boston Harbor. As part of the compromise with preservationists, the state agreed to fortify three structures and contribute roughly $500,000. The work will remove asbestos and seal the structures to slow decay and prevent break-ins.

The immediate goal, Powers said, is to preserve salvageable structures such as the quartermaster’s building for future use. With sweeping views of the Boston skyline, curving banisters, and fireplaces, it could make an exceptional inn, he said.

The work will also clear Norway Maples, staghorn sumac, and other dense growth, which thrived as the land lay fallow.

The campground will include 10 individual sites, a large area for a group, and, by next year, the construction of six yurts, permanent tent-like structures that will make it easier to spend the night.

Peddocks is the second-largest of the 34 islands in Boston Harbor’s national recreation area, a 210-acre expanse off the town of Hull that looks, from the air, like a malformed dumbbell. Its rounded hills are linked by flat spits of sand. The fort sits on what is known as East Head; elsewhere on Peddocks are the remnants of a Portuguese fishing village that is still home to seasonal cottages.

Construction of what would become known as Fort Andrews began in 1898 with the formation of enormous earthen mortar batteries on East Head. Over the next decade, the government built a collection of Colonial-revival-style brick structures with granite foundations, ornamental cornices, and several barracks with majestic double-deck porches facing a grassy parade ground.