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

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

The final resting place of the poets Shelley and Keats.

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

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

A hidden three-foot-wide house separates these two regal churches.

The stunning interior of this Gothic church is covered in ornate gold details.

Ancient catacombs form the foundation for this Rococo orgy of a church.

The final resting place of the great navigator, or maybe his brother.

Commonly acknowledged as the only public monument to the Devil himself.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

The world's oldest bookshop still in operation.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

The sixth of London's "Magnificent Seven" cemeteries, and a source of unlikely inspiration to Beatrix Potter.

Eighty million natural history specimens call this gargantuan museum home.

Pop culture has helped to keep this iconic British building from being destroyed.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

The curios of pharmacist and collector Henry Wellcome.