Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

Obscure Freemasons still live in D.C.’s largest private residence.

Corn-inthian columns with a uniquely American take on neoclassical architecture.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

Behind an abandoned storefront is an example of pioneering 1930s gas station architecture.

This forgotten boat elevator was an engineering marvel in its heyday.

This poor little statue is the most vandalized memorial in Washington.

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

Every drop of D.C. tap water flows through this old waterworks.

A diminutive plaque recalls the treetop sniper who almost killed Abe Lincoln.

Please don’t anchor your boat onto the Department of Defense’s underwater data cables.

These recently uncovered walls are all that's left of Washington, D.C's first defense contractor.

Perhaps the most scandalous statue of America's first president.

She stares out across six lanes of traffic, clutching a musket and infant with determination.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

An ear-piercing buzzer calls lawmakers to a vote with a series of long and short rings to form coded messages.

A fantastic array of trays and cables once whisked books over to the Capitol at 600 feet per minute.

Cold War intelligence agents monitored communist embassies from an attic in a former pigeon coop.

Senators used to relax in the nearly forgotten marble tubs now hidden in the U.S. Capitol Building's basement.

The institution is sitting on a goldmine of 21,000 paints, varnishes, pigments, and primers preserved for posterity.

This suburban house is made of dirt, and almost sparked a revolution in home construction.

The early data processor factory founded in Washington for the 1890 U.S. Census went on to become IBM.

A small token of gratitude from freezing cold journalists who were given a warm haven while covering JFK's inauguration.

The rogue roots are gradually consuming some of the historic marble grave markers.