Railroad officials in the early 1900s sought to spare travelers the sight of Roman soldiers’ private parts.

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

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

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

This statue of the "father of television" stands prominently in the United States Capitol.

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

An unassuming, powerful monument north of the U.S. Capitol bears witness to the resilience of Japanese Americans during a time of grave injustice.

Giftshop catering to cryptozoologists and anyone with a sense of humor.

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

The "lovely red Vega" of the legendary record-settling pilot.

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

A tiny piece of the Moon is embedded in this stained glass masterpiece.

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

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

When it opened during the final years of the embargo, all the drinks and cigars were free.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

The 28,000-year-old specimen is remarkably intact.

Sit where JFK proposed to Jackie or where Nixon dined on meatloaf at this storied pub.

Before Nixon, "watergate" meant canals.

Helen Keller once broke ground on this historic center for the study of technologies to benefit the hearing impaired.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

A building shaped like the Army Corps of Engineers logo, because why not?