An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

Used as an example in one of the first dictionary entries for "museum" in 1706.

France's most famous cemetery, with some of its most curious tombs.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

One of Catholicism's four major basilicas has a series of papal portraits that are said to predict the end of the world.

The studio built by fascists in the hopes of "reviving the film industry" with the occasional propaganda film opportunity thrown in.

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

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

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."

An enormous park-like oasis, full of famous Chicagoans’ graves.

A haunting statue called "Eternal Silence" has quite the reputation among visitors with active imaginations.

A gothic church spire sits atop this skyscraper, the tallest church in the world.

A Bibliophile's Dream.

This morbid, delightful curiosity shop offers everything from animal bones to human teeth.

This whimsical Oz-themed park had a wonderful impact on the surrounding neighborhood.

A place to eat for on-the-run agents and espionage enthusiasts.

A semi-scholarly approach to sex.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

A speakeasy takes on Chicago's drinking culture.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

This intricately carved and hilariously huge bed was such a famous symbol both Shakespeare and Byron used it in their writing.

Lovers proclaim their unbreakable bond by leaving their names on locks fastened onto the Shoreditch fence in East London.