​Preserving our nation's film heritage

We're taking a peek inside a time capsule full of our country's best-loved movie memories. Martha Teichner leads the way:

The vaults look like they're straight out of some sinister, surreal movie. Monsters lurk behind these locked doors -- like the original camera negative of "Frankenstein," from 1931, starring Boris Karloff -- and treasures.

Greg Lukow, who heads the Library of Congress' National Audio-Visual Conservation Center in Culpeper, Va., showed Teichner an untitled, experimental short (which they've dubbed "Newark Athlete"), which was made by Thomas Edison's studio in 1891. "It may be the oldest piece of celluloid rolled motion picture film in the world," he said.

"Newark Athlete" was added to the National Film Registry in 2010. The Registry is a compendium of films deemed historically, culturally or aesthetically important enough to preserve for future generations. Films are nominated for the Registry by film professionals, scholars, and the public.

This year's additions will bring the list to 650 -- a tiny, tiny fraction of the collection the Library of Congress stores here. The largest anywhere, its collection has 1.4 million films, TV and video recordings.

If this place suggests a secret, Cold War bunker, that's exactly what it used to be.

"It was a nuclear bomb-proof underground bunker that was a part of the U.S. Federal Reserve Bank system," said Lukow. It was where billions of dollars of coins and currency was stored for use after a nuclear attack -- "just sat there for 25 years, between 1968 and 1993, for the purpose of re-pumping the economy."

Built in a former bomb shelter, the Library of Congress' National Audio-Visual Conservation Center stores 1.4 million films, TV and video recordings that tell America's story. CBS News

At the end of the Cold War, the bunker was decommissioned. In 1997, philanthropist David Woodley Packard bought the facility, transformed it, and then gave it to the Library of Congress.

Every year the Library of Congress adds another 25 titles to the National Film Registry. But a film has to exist to be eligible for inclusion.

Seventy percent of the 11,000 or so silent films made in the United States have been lost. The ones that survive are often incomplete, and in terrible shape.

Until 1951, most motion picture film was made of nitrate, which had a tendency to decay, catch fire, or even explode if not cared for properly.

Film archivist George Willeman showed Teichner a roll of film which had been kept someplace "very, very wet, and it has become what we call a hockey puck."

Another film reel showed signs of "honey drops" -- "The base is deteriorating and squeezing up through the winds of the film," said Willeman. "This one still has a little bit of image on it, so there is something there we can try to save."

Examples of deteriorating nitrate film prints. CBS News

Saving our cinematic heritage is a big part of what the Library of Congress does at its Packard Campus in Culpeper. In its lab, technicians can take the faintest of images and, by using state-of-the-art photographic techniques, actually make brand new negatives and prints.