The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

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

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

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

An easily overlooked memorial to a Ukrainian famine-genocide that killed over 4 million people.

The first memorial dedicated solely to the Black troops who fought for the Union.

This lovely pocket park is one of the most under appreciated in D.C.

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

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

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

It was once the base for a series of domestic terror attacks.

You could be standing at the site of one of D.C.'s most fatal tragedies and not even know it.

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

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

America's Most Wanted's set resides in this tribute to the history of crime and punishment.

A much-maligned monument to teetotalism.

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

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

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

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

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.