Places Nikolas Flamel Wants to Go

The oldest monument in Marrakesh and the city's only surviving example of Almoravid architecture.

The other side is actually green.

Mosaics, storks, and brothels—this ancient city has it all.

The final resting place of the great navigator, or maybe his brother.

One of Antoni Gaudí's least-visited works, an homage to Catalan patrimony that mixes neo-Gothic with Modernista forms.

A massive base for the Nazis' most formidable weapon in the Atlantic.

The encased skull that is widely believed to belong to St. John the Baptist.

This futuristic observatory at the top of the Pyrénées offers unrivaled views.

The great Italian Renaissance painter was laid to rest here in the Chapel of Saint-Hubert.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

Statue of death tucked in the University of Medicine courtyard.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

The history of radiation is on safe display at the foot of a radiation science laboratory.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

A mechanized clock where a man fights off a dragon, crab, and rooster.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the 20th century.

The oldest stone house in Paris was built by its most famous alchemist.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

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

A former mining village that now operates as an open-air museum.

A collection of wax anatomy by the great sculptor Clemente Susini.

Once one of the largest sites of silver deposits in Italy.

A serene mountaintop temple complex featuring one big, bronze Buddha.

This Gallo-Roman sanctuary is dedicated to Serápis, god of the underworld.