For the past eight years, Bruce Zaccagnino has been leading parallel, paradoxical lives. In all that time, the 55-year-old entrepreneur has scarcely ventured more than a few miles from his home in Flemington, N.J., and he has never in his life set foot on a train. On the other hand, he has built what may be the most extensive model-railroad layout in the world, a lovingly crafted monument to the romance of train travel, as well as a thriving commercial enterprise. Covering 52,000 square feet—with roughly eight miles of track, more than 400 bridges and 400 tunnels, and scores of handcrafted buildings on meticulously detailed terrain—the creation stands as the Mount Rushmore of scale modeling. "As an artist I felt compelled to give this to the world," says Zaccagnino.

The question was, would the world feel compelled to receive it. Like most obsessions, Zaccagnino's started innocently enough. He began in 1973 by building a modest layout in his basement. As the amount of track expanded, he was forced periodically to find more space. "We had to build five cellars onto the house, he had so many ideas," says his wife, Jean, who enthusiastically supports her husband's hobby. "He'd tear things down to try something new."

In 1991, the couple, who have been married 27 years, bought a 16-acre site, and Bruce set to work building what he called Northlandz (the final "z" stands for his last name). Financed by bank loans and the sale of the Zaccagninos' home, the project required more than four years of 18-hour days to complete. Since opening for business in 1996, Northlandz has attracted nearly 400,000 visitors, including rocker (and model-railroad buff) Rod Stewart. Zaccagnino is installing a 35-foot steel bridge and sees no reason not to keep expanding. "Why this hasn't been done before," he says, "is a mystery to me."