Art deco landmark on the outskirts of Washington, D.C.

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

The towering figures were created from the cemetery's fallen old-growth trees.

It took 160 years to complete the most ornate church in Ecuador.

A secret greenspace hides atop a Capitol parking garage.

The discovery site of the "Capitalsaurus," the official dinosaur of Washington, D.C.

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

The hidden offices underneath Memorial Bridge have been locked up since 1976.

Housing the National Women's Party since 1929, this historic house is now a monument to the fight for gender equality.

Seemingly unremarkable items like empty sushi trays, chef hats, and freshness stickers are being preserved so future generations can look back on this beloved cultural import.

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

Where the U.S. government kept its actual treasure, before Fort Knox.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

In the basement of the U.S. Capitol Building is a hidden storage room full of ornate floor tiles leftover from the 1850s.

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

The privately owned cemetery that holds room for Washington's finest when they step down from life.

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

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

A super-sized promotional trick that is now a D.C. landmark.

An obscure public service from the U.S. government that redeems burnt, moldy, and soiled old greenbacks.

Largest Roman Catholic church in North America.

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

Government testing at the asylum briefly explored using marijuana as a "truth serum" on Nazi prisoners of war.

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