Leave a trinket at this artistic collection of mailboxes.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

Featuring a meatless buffet fit for kings, this family-owned Zurich eatery is considered the oldest vegetarian restaurant in the West.

Visit the ancient, mysterious Roman catacombs ... in the Netherlands.

These 12th-century catacombs carved into a mountainside were a place of mysticism and Christian hermitages.

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

These lesser-known Maltese catacombs date back over 1,700 years.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

A hidden gem in the middle of the city's infamous Jewelry Quarter.

Overshadowed by other, more famous Maltese catacombs, this ancient burial chamber has one of the best examples of a ritual agape table.

The Neapolitan Cult of the Dead still cares for the skulls at this mini-Fontanelle.

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.

The burial place of an obscure North African saint was turned into a macabre body preservation factory for the 17th-century Neapolitan elite.

A dead saint, a deadly poison, and a mysterious holy ooze.

A daily pyrotechnic celebration marks a beloved tradition during Valencia's festival season.

Vibrant street art created with mixed media.

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

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

This house's itty bitty size means no humans allowed.

Bold black and white motifs of life and death add a dramatic flair to this 17th-century crypt.

Never actually a tree at all, this spot was the site of London's public hangings for nearly 600 years.

Hidden in the courtyard of the Victoria and Albert Museum is a little-known tribute to two celebrity pooches.