Wall after wall of this French seaside neighborhood is intricately decorated with seashells and corals.

What if all public housing projects had been designed by "the Pygmalion of modern architecture," not only their prototype?

This mountain trail inspired Nietzsche to complete his magnum opus.

Artist Danielle Jacqui decorates nearly every inch of her home inside and out with her work.

This hidden garden boasts amazing views of Lyon.

This triumphal arch celebrating the Sun King's conquest of Lille is a masterpiece of military architecture.

100-windowed castle turned art gallery, built by one dedicated mason.

Lyon's "Wall of the Silk Weavers" is one of the largest murals in Europe.

The opulent home that inspired Tintin's Marlinspike Hall and the adventures within.

Claude Monet was baptized in this lavishly ornate Paris church.

This modern museum of Mediterranean culture is surrounded by a surreal concrete honeycomb.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

This otherworldly French waterfall looks like its waters have turned to stone.

Miles of man-made caves and tunnels are currently used for cultivating mushrooms.

Hundreds of dwarf beeches create an unusual, haunting forest in the north of France.

The Church of the Annunciation was carved into the face of a cliff, just like the rest of the town of Haute-Isle.

These crumbling Nazi artillery bunkers are now fair game for massive graffiti projects.

Tables of secondhand books fill the inner courtyard of this 17th-century stock exchange.

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

A simple plaque on the facade is the only reminder that the treaty ending the American Revolution was signed inside.

The sunken structure looks like the victim of a catastrophic flood.

A chapel on a volcanic core, marking the end of a successful journey.

Hundreds of secret cabinets built into the walls of legendary poisoner's private work room.

What looks like a normal building is really a hollow facade hiding a subway vent.