Mysterious chains and iron stakes adorn this strange grave, with no explanation.

The abandoned summer estate of the former Greek Royal Family.

This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

The mystery of this small, brick pond eluded its possibly only investigator until his death.

At high tide this strange footbridge appears to have no purpose whatsoever.

A Japanese cat island also populated by the descendants of a band of banished samurai.

Peruse rare tomes like poetry bound in pearls or books with branches and berries growing out of their spines.

The final resting place of the famous Rhode Island lighthouse keeper who heroically saved dozens of people from drowning.

A meandering boardwalk across the bogland leads to a "stairway to heaven" with sublime views.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

The ancient necropolis houses the immense rock-cut tombs of four Persian kings.

The weathered grave of a medieval anchoress who walled herself up in a cell attached to a church.

A midcentury ranch house hides a literal treasure trove of unique rocks and minerals.

Western Europe's only representation of a Roman goddess still in its original location sits in an unassuming park.

The oldest and smallest cemetery in Paris is only open to the public twice a year.

At the United Kingdom's only residential library you can sleep among the books.

A home built with marble tombstones from the graves of 2,200 Union soldiers buried in a Virginia cemetery.

An Irish church where an 800-year-old mummy is reaching out of his coffin as if to shake hands.

The mummified heart of Louis XVII, the lost dauphin of the French Revolution.

After the famous composer died in Paris, his sister snuck his heart out of the country to honor his wish that it be buried in their native country.

When the imprisoned pope's remains were finally returned to the Vatican, his heart stayed behind in France.

In the best of all possible worlds, everyone will get a chance to see this statue in which Voltaire's heart is interred.

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

The heart of a Scottish legend had a centuries-long journey before reaching its final resting place.