Crammed into a Baltimore row house is an oddities shop that sells everything from skulls to dead insects.

A pair of giant roadside arrows are all that remains of a former Route 66 trading post.

A stealthy Apache hideaway that became the haunting site of a mass grave.

The story of Two Guns, Arizona could easily be described as a Shakespearian tragedy on Route 66.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

Electronic inventions that resulted in products and systems we use every day are on display in this labor-of-love museum.

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

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

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.

Cold War intelligence agents monitored communist embassies from an attic in a former pigeon coop.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

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

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

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

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

A Civil War fort in the middle of Washington, D.C. has been swallowed by a forest.

This leafy estate is worth $18 million and is so grand it has two mailing addresses.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

A painfully obvious spy house sits right across the street from the Russian Embassy.

A wondrous old library overlooking the nation's capital.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.