At one of Berlin’s oldest churches, visitors can place mosaic tiles to help restore a medieval mural.

This amazing abuela became a diehard metal fan late in life and an icon of Madrid's '80s rock scene.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

The lengthy skeleton of one of the tallest Spaniards of all time is on display in Madrid.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

A spiralling hourglass-shaped tower rises from the forests in Denmark.

Generations have refused to move this doll from its dusty resting place to preserve a castle from a watery fate.

In legend, this ancient dolmen was said to have been created when a troll tried to destroy a church.

A public display of random paleontology.

Four alabaster giants contemplate the tides on the shore of Denmark.

A perfectly circular stronghold constructed in the 10th century is now a nucleus of Viking culture housing a museum, village, and reenactment of an epic Viking battle.

This secret collection of the strange and occult was rediscovered in a forgotten room of an old house.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

Armenian monks at an island monastery in the Venetian Lagoon make a rare rose petal jam.

Hanging within this medieval church are the bones of a beast allegedly slain by a fourth-century saint.

The mummified relic of St. Antoninus.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

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

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

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

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

Bored potato-guarding Nazis etched their thoughts onto a brick storage building in Copenhagen's Meatpacking District.