A tour de force of a fountain, memorializing a man who loved fountains more than anything else.

An Irish Memorial commemorating those who perished due to potato blight.

Yo, Adrian!

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

Standing for over 200 years, the abandoned home of a Revolutionary War hero and later a succession of prison superintendents.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

Hear the quietest sound from across the dome.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Long the exclusive domain of birds and vagabonds, this little-known Central Park peninsula is open to the public once more.

There are owls with glowing eyes in Herald Square.

Commemorating the spot where the famous scientist fed his pigeons.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

The oddly shaped, steam-spewing building is now an art studio and gallery.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

Las Vegas's very own 40-foot-tall fire-spewing praying mantis.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

These banned cigarette vending machines now sell little pieces of pocket-sized art.

An overlooked monument to the celebrity gangster who helped put the sin in Sin City.

An exotic wildlife habitat right off The Strip.

The second-largest gold nugget in existence, displayed in a Las Vegas casino conveniently named the Golden Nugget.

Flashy signs from Las Vegas’s past find their final resting place at this unusual graveyard.

At 135 years old and counting, this historic print shop is heaven for poster nerds and music buffs.