With its decaying Asian pagoda, crumbling English castle and the remains of a resort hotel, National Park Seminary looked like an enchanted forest – one in desperate need of a happy fairy-tale ending.

But thanks to a Madison-based company’s $150 million redevelopment project and local preservation efforts, the seminary and its 19th-century structures are being preserved as both a residential complex and public historic attraction just off the Capital Beltway.

The Alexander Co. of Madison developed the project, which includes 65 apartments and about 150 condos, townhouses and single-family homes.

Single-family homes are being built into the castle, pagoda, bungalow or Dutch windmill. Condos can be found in the Queen Anne-style hotel or in the buildings around it, such as a former chapel that still has stained-glass windows, or the “Aloha House,” a large stucco estate home with brick arches and maiden statues.

The townhouses are new construction – but with English Tudor and Dutch Flemish designs.

“It’s kind of like a fantasy land,” said Dan Peterson, a spokesman for the Alexander Co., which specializes in restoring old site s for modern use. “There’s nothing like it in the country.”