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

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

The oldest botanical garden in the world that technically isn't the oldest.

The incorrupt tongue of the patron saint of lost things is venerated in this basilica.

Built to repay the sins of the father, this church is home to one of the most valuable works of Western art.

Italian poet Dante Alighieri is entombed in this small mausoleum in Ravenna, and his hometown of Florence has never been too happy about it.

Filled with goldfish swimming in a shallow pool of sea water, this ancient crypt is more wishing well than burial site.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

Renaissance hospital featuring a rotating door into which unwanted babies were dropped.

The middle finger of modernity.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

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

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

Jesus' footprints and the first catacombs in the world.

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

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

Astounding collection of coin-operated games and automata.

The first car-centric shopping plaza in the U.S. brought a little bit of Spain to downtown Kansas City.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

A chessmaster's dream destination.