This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

The tallest The Church of Jesus Christ of Latter-day Saints temple in the world soars above the Beltway.

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

A star fort along the C&O Canal in western Maryland that protected America in three wars.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

The site where Poe "in great distress, and ... in need of immediate assistance" likely died.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

Once connected to the outside world by a single train track, this ghost town is looked after by the National Park Service.

What was once the largest NFL stadium.

This spectacular public market has got meat, fish, vegetables, baked goods, and enough kielbasa for a lifetime.

This massive airship factory is so large that it has its own indoor weather.

An unoccupied lighthouse encased in layers of ice from the waters of Lake Erie.

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

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

There’s a special club house at the top for the bell ringers.

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

Decades before the scandal, this staircase on the river was a literal "water gate."

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

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.

This leafy estate is worth $18 million and is so grand it has two mailing addresses.

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

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

Home to items never before seen by the public.