This massive, ancient stone was disassembled and then put back together again.

The Victorian-era greenhouse is stuffed with tropical plants, and open 365 days a year.

This unusual structure may be on its way to becoming a cultural landmark in Toronto.

This knick-knack-covered house (complete with a matching van) is a charming oddity in the middle of a modest downtown neighborhood.

Reputedly the smallest jail in North America.

Smallest house in Toronto sits on a lot meant to be just wide enough for cars to drive through.

Outside of one of Britain's most renowned social clubs, a step installed specifically for the Duke.

One of America's founding fathers lived in this London lodging between 1757 and 1775.

This coffee shop lies hidden beneath a historic church.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

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

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

London's smallest police station is barely the size of a phone booth.

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

This trail was once used to smuggle cigarettes, sugar, and other black market goods between Italy and Switzerland.

A space dedicated to contemporary art and culture, co-chaired by fashion icon Miuccia Prada.

See what remains of a once grand ancient Roman circus.

One of the world’s smallest bars, just 13 square feet, is brimming with speakeasy flair.

The secret medieval communication system will whisk your words above the noise of the crowd.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

A larger-than-life house of cards stands outside the house of a former fashion designer.

Just across from the "Last Supper" painting is the famous painter's vineyard, a gift received for creating the masterpiece.

A dilapidated psychiatric facility on the outskirts of Milan where electroconvulsive therapy was developed and Napoleon once lived.

Vast network of air raid tunnels beneath Lombardy's capital.