A wondrous old library overlooking the nation's capital.

A hoard of sky catalogs, astrophysical journals, even the works of Galileo and Copernicus.

The site of the climactic scene from the classic horror film is now a historic landmark.

Home to items never before seen by the public.

The "lovely red Vega" of the legendary record-settling pilot.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

A Spiritualist house of worship where believers communicate with the dead in the spirit world.

This small hilltop church weaves the urban history of Washington, D.C. with the national history of the United States.

The 28,000-year-old specimen is remarkably intact.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

Look closely and you’ll notice that the color changes a third of the way up the tower.

For 60 years, the academy had no permanent location until members voted Washington D.C. as its forever home.

The house where John Wilkes Booth conspired with his co-conspirators.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

People escaping slavery may have hidden inside a corpse vault.

This Masonic lodge was the first major private building to be constructed in Washington, D.C. after the Civil War.

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

Coins and medals straight from the mint await visitors to this shop in the nation's capital.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

Also known as the Founding Church of Scientology.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

Obscure Freemasons still live in D.C.’s largest private residence.