The preamble to the U.S. Constitution written entirely from vanity license plates hangs in the Smithsonian museum.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

The first presidential bomb shelter was located in an old vault under the Treasury, connected to the White House via tunnel.

The privately owned cemetery that holds room for Washington's finest when they step down from life.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

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

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

The walls of the iconic dome are hollow and have a secret stairway.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

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

A historic neighborhood church is reborn as a psychedelic arts collective.

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

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

Home to items never before seen by the public.

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

The United States Capitol's former columns still stand.

No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

Ancient serpentine sacrifice holder that has stood the test of time.

A fountain standing as a testament to a doomed alliance.