This ancient Roman arch misled treasure hunters for centuries.

The ruins of an abbey believed to have been founded by Charlemagne in the 9th century.

A wunderkammer of curious objects and intriguing art nestled within a hub of ancient Roman sites.

The mystic whose incorrupt corpse still attracts the faithful.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

Jesus' footprints and the first catacombs in the world.

A fairy tale castle in modern Rome.

The underground sanctuary of a mysterious ancient cult.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

Museum housed in underground tunnels that date back to Buenos Aires's earliest settlements.

A gateway to a mysterious network of underground tunnels.

This historic, palatial theater is now one of the world’s most beautiful bookstores.

This informal museum is a magical trove of anonymous art collected from car boots and flea markets.

A traditional American farmhouse plopped in the middle of a Piccadilly courtyard.

A comic book store that puts the marvel back in marvellous.

Since 1874, this macabre collection has developed into a museum devoted to Scotland Yard's mementos of dastardly deeds.

The beloved beast's taxidermy remains sit in the Natural History Museum's cafe.

This iconic high-rise residential block was one of the last to be built in the Brutalist style.

The remains of a historic football stadium that once hosted 50,000 spectators.

This toxic spoil heap found a second life as a ski slope, popular film location, and wildlife haven.