12,000 sq. ft. museum tracing erotic art from antiquity to modern times.

This highway overpass was named after the tragic disappearance of a young mother who got mixed up with the wrong people.

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

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

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

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

D.C. once had its own tiny rival to the New York Stock Exchange.

A rotating cast of guys and dolls in front of a Washington, D.C. building.

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

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

A line of blue paint marks the route of the inaugural parade.

When it comes to handsignals (and colonialism) rock always beats scissors.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

An obscure federal monument honors the French diplomat who served as Ambassador to the U.S. during WWI.

The span is crooked and made from two older recycled bridges.

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

An overlooked oasis of quiet on the grounds of Washington's monumental basilica.

The school tested mustard gas for the U.S. Army during World War I.

A hoard of sky catalogs, astrophysical journals, even the works of Galileo and Copernicus.

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

There’s a hidden military meme engraved on the World War II Memorial.

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

Need a hardcopy of the 50-title Code of Federal Regulations? This is the place.

A celebrity from the late Cretaceous period.