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

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

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

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

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

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

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

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

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

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

An Industrial Revolution-era public work that purified water using nothing but sand.

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

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

The first presidential bomb shelter was located in an old vault under the Treasury, connected to the White House via tunnel.

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

A historic ruin just 20 feet away from a busy highway onramp.

Decades before the scandal, this staircase on the river was a literal "water gate."

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

A celebrity from the late Cretaceous period.

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

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

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

Once the supplier for noteworthy projects like the National Cathedral, this old brickworks now lies abandoned.

The most accurate timepiece in the world.