In the modest family room of Kermit Weitzel's home in New Britain, Pa, the blue shag carpet has a rectangle impressed into it, as though a heavy piece of furniture had settled there.

That rectangle is actually a trap door. Weitzel has to pry it up with a screwdriver. It opens to a 12-foot deep hole lined with concrete block. The chamber is 9 feet by 9 feet.

Weitzel built this fallout shelter himself, in 1963, from government-issued plans. The 85-year-old World War II veteran used to keep it stocked water and canned food, but not anymore.

"Almost 50 years, since they had that scare," said Weitzel. "I won't be around to see the next one, that's for sure."

His wife, Helen, has never liked the bomb shelter, but Weitzel is clearly proud of it, even if now it only houses a water pump for his well. He's the only person he knows who has such a shelter.

Fifty years ago, the U.S. government wanted a network of fallout shelters across the country, in municipal buildings, businesses, and private homes. Copies of the plans are now on display at the Mercer Museum in Doylestown, as part of an exhibition called "Alert Today, Alive Tomorrow: Living with the Atomic Bomb."

It features government posters; movie memorabilia from atomic-scare flicks such as "Them!"; toys such as "Atomic Bomb" goggles; and radiation detection kits. In the 1960s, the specter of the atomic bomb was everywhere.

"Americans were inundated with messages about surviving, and living with new global reality of the atomic bomb," said Cory Amsler, vice president for collections at the Mercer.

Today, few people worry about atomic fallout. Many people who bought houses with pre-existing fallout shelters ignore them. Only their yards have tell-tale air vents popping up from underground.

Georgie Coles moved into her farmhouse near Solebury 10 years ago. As survival bunkers go, this one is palatial -- about 500 square feet. She does not use it for anything, not even storage. It's mostly just a conversation-starter.

"I have a lot of receptions here for the Chamber of Commerce, the hospital, things like that, and people always want to come and look at it," said Coles, who runs a landscaping nursery. "So it is well known that it is here, and it is a tourist attraction I guess you could say. One of my grandchildren wanted to have a birthday party down here."

Revisiting past fears

When George Wozar bought his Chalfont Borough house in 1970 and in, he was surprised to discover a previous owner had built a fallout shelter under the garage. He hasn't been inside it for almost 40 years.

At the request of a reporter (and his wife, Janis), Wozar cleared away the scrap wood that had been accumulated at the door of the shelter for years, and peeked inside. There is no electricity, and the ceiling is so low, an adult cannot stand upright.

His 3-year-old granddaughter, Joselyn, was fascinated.

"There's a spider and a skeleton," announced Joselyn. "They're toys."

The previous owners had a boy named Bobby, who used the shelter as a gloomy play area. Over the threshold of the shelter, he had written in chalk "Bobby's Spookhouse." Inside, there is a plastic mummy and a rusting thing that might have once been a radio. The pièce de résistance in the corner -- a rotting Ouija board.

"It's disintegrated after 50 years," said Wozar.

He clearly remembers duck-and-cover drills from his childhood, and wonders if those times are coming back.

"With anti-terrorism drills, we're almost going back," said Wozar. "It's like we're recycling."

Audio slideshow by Lindsay Lazarski