Lynnewood Hall, a century-old stunner of a building just outside Philadelphia, silently, almost invisibly, languishes 200 feet beyond a two-lane blacktop road like a crumbling little Versailles.

The graceful fountain that welcomed hundreds of well-heeled visitors, President Franklin Roosevelt among them, was dismantled and sold years ago. Its once meticulously sculpted French gardens are overgrown with weeds and vines. The classical Indiana limestone facade may have lost its luster but its poise still remains — at least from the other side of rusted wrought iron gates that keep the curious at bay.

Like other Gilded Age palaces of the nation's pre-Depression industrial titans, Lynnewood Hall is a relic of a bygone era facing an uncertain future. Will it befall the same fate as neighboring Whitemarsh Hall, the demolished mansion of banking magnate Edward Stotesbury? Or will it be returned to former glory, like industrialist Alfred I. duPont's former Nemours Mansion in Delaware?...