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

The oldest operational cathedral in the U.S. has one shell of a way of projecting speakers' voices.

The final resting place of a famous 19th-century murder victim whose identity is still a mystery.

The fanciest public restroom in New York City boasts fresh flowers, art, and a classical music soundtrack.

This Georgian architectural masterpiece is the only cloth hall left in Britain.

This tallest folly in the world began its life as an elaborate factory chimney.

This abandoned Greek island was the last active leper colony in Europe.

The Grand Lodge of Ireland is one of the oldest in the world, full of fantastical, elaborately themed rooms.

An enormous steel waterfall is a nod to the substance that shaped Britain's Steel City.

A mysterious plaque to the even more mysterious "Fr. Pat Noise," killed in "suspicious circumstances."

A small but hugely whimsical theater where marionettes play out the "The Battle of Stalingrad."

These lush botanical gardens employ the most purrfect pest control force.

This meticulously extracted nervous system allegedly came from a 19th-century custodian who donated her body to science.

At this rare mosque in Tbilisi, Sunni and Shia Muslims pray side by side.

A mine fire has been burning under the deserted town since 1962, but this church is still going strong.

The mysterious canine hides atop a drain pipe on the back of the building, some say as a sneaky shoutout to Yale.

An Art Nouveau gem hides beneath the layers of city grime obscuring this once-magnificent building.

This strange, big-tailed beast became a Pennsylvania town's unofficial mascot.

An abandoned Byzantine fortress and notorious prison.

The beloved fantasy novelist is buried near a church containing a whimsical etched glass window full of Narnia favorites.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

The enchanting archway is the only surviving portal into Dublin's lost medieval wall.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.