What are Notre Dame's gargoyles guarding? What do five ordinary flagstones have to do with one of the most notorious killing machines ever created? What is the Phantom of the Opera's connection to a statue on the Seine? Paris has one of the richest and most exciting histories of any city in the world but some of its most fascinating stories have been lost to the ages. Enjoy this one-of-a-kind tour as we reveal its many secrets, hiding in catacombs and cathedrals, sidewalks and cemeteries, and along its famous river.

Six experts set out in search of some of New York's most remarkable hidden stories. Why guests can't go up Lady Liberty's torch; What's behind the famous 21 Club's secret door; how the city's top tourist attraction put cowboys out of work.

A unique tour of Berlin hunts for little-known stories hidden in the city's famous landmarks, obscure sites, and even in the food.

Highlighting some of the most amazing stories from London that has never been heard before. A unique tour of London explores objects with secret histories, including its black cabs, the Marble Arch and the Horse Guards Clock.

Five experts go searching for some of San Francisco's most remarkable and surprising secrets. An exploration of little-known stories behind San Francisco landmarks and locations, including its golden fire hydrant and Dutch windmills.

In the final episode, discover where to get a Michelin star meal for less than three dollars and learn the amazing history of Hawker Food; and tour Singapore with “Toilet Man” to find out how beautiful gardens and obsessively clean toilets made the city rich.