One of only two remaining Victorian-era greenhouses in New York.

A Victorian cemetery in the heart of Brooklyn remains a popular mecca of morbid curiosity.

The rogue roots are gradually consuming some of the historic marble grave markers.

One of the three perfect vellum copies of this historic book known to exist is on display in a specially-designed case.

This groundbreaking 16th-century map is known as "America's birth certificate."

A nostalgic bibliographic gem.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

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

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

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

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

This statue of the great Argentinian car driver is located near a famous curve of the Monaco Grand Prix.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

This saucy statue once caused outrage among locals.

Dive bar built out of the remains of a whaling ship.

The newsstand that never closes its doors—well, almost never.

Yo, Adrian!

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

Alexander Hamilton’s creation caused quite a bit of controversy.

This elaborate towering structure was once famed for its revolutionary height.

Huge masonic hall in Philadelphia with lavishly themed rooms.

This beloved marketplace mascot poops money and grants good luck.