Largest Roman Catholic church in North America.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

At 207 feet, one of the world's longest continuous escalators.

Helen Keller once broke ground on this historic center for the study of technologies to benefit the hearing impaired.

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

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

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

Home to items never before seen by the public.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

San Francisco's newly reopened hands-on science museum.

The largest whiskey stash on the West Coast survived the 1906 fires--but not without heroic effort.

Noble beasts perhaps, but not the Emperor's dogs.

Gold Rush ship-turned-hotel buried underneath San Francisco's financial district.

Faceless white figures loom over the city from the rooftop.

San Francisco's oldest surviving monument and meeting place for 1906 survivors.

Only hotel where you can legally launder money.

A still functioning vaudeville carousel that has operated for over a century boasts a colorful menagerie and past.

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

These subterranean storage areas hold emergency water reserves.