The first purpose-built art gallery in the United States is once again open as a center of craft arts.

A museum cafe showcases Native American dishes and indigenous ingredients from across the Western Hemisphere.

The most decorated dog of World War I is preserved in the Smithsonian.

The oldest continuously operating fish market in the United States.

The national park was once a plantation estate.

There’s a hidden military meme engraved on the World War II Memorial.

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

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

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

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

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

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

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

This grand gothic brewery has been pumping out suds for over a hundred years.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

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.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This massive statue is the personification of Bavaria and the first colossal statue of the modern period composed of bronze.

This airport currywurst stand is made out of retro airplane parts.

This tribute to the 16th-century composer is now an unusual shrine to Michael Jackson.

The telescope that discovered Neptune.