This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

Cat art as far as the eye can see.

A rare tour of an aristocrat's private home reveals valuable 17th-century paintings from artists like Rembrandt.

This cheese shop also houses a museum devoted to Dutch dairy.

The former home of a mad diplomat is said to still be marked in bloody, arcane scrawls.

A Portuguese Jewish cemetery filled with stunning grave monuments that date back to 1614.

America's greatest forgotten garden and the former stomping grounds of Son of Sam.

This hermitage celebrates the legend of Emperor Constantine's healing from leprosy.

Known for centuries as the famous Roman emperor's burial place, this monument is actually something else.

Hidden within this iconic mountain are a set of World War II bunkers once used by German forces.

Roman politician Herodes Atticus built this nymphaeum to honor his wife, whom he may have murdered.

A burial vault located under Tiber Island in the middle of the Italian capital.

One of seven Jewish catacombs in Rome and one of only two open to the public.

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

A collection of objects supposedly singed by the hands of souls in purgatory.

The final resting place of the poets Shelley and Keats.

The yawning maw of this pagan visage is said to bite off the hands of liars.

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