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

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

Was there a small "backpack nuke" hidden in the attic? JFK apparently thought so.

The sculptor was instructed to add “stallion attributes” to the general's bronze mare.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

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

This unique historical monument features large concrete spheres designed to resemble fallen stars.

The Pentagon is so large that it was planned like a city, complete with internal highway infrastructure.

The moving metal works of one troubled artist can still be viewed on his front lawn... for now.

Victorian "Fancy Craft" Hair Wreaths and Relics.

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

This grand stone tower was dedicated to a famed American humorist almost by coincidence.

This Boeing KC-97 tanker is now a restaurant for aviation lovers.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

The largest source of fossilized insects anywhere.

Home to items never before seen by the public.

A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

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

The oldest continuously operating fish market in the United States.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

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

The romance of early commercial flight still fills this Art Deco destination.

Washington's iconic carousel has a nice piece of Civil Rights history.