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

The world's tallest bridge is also possibly the most elegant.

A mosaic-tiled house built by graveyard sweeper Raymond Isidore.

A public park off the beaten path with a beautiful waterfall and 13th century Cistercian abbey.

This museum in a Paris apartment gives a unique look at the iconic French singer's life.

The mental institution where Van Gogh created some of his most famous work now allows guests to walk in the artist's footsteps.

At Monet's beloved home you can still see the Japanese bridge, waterlilies, and weeping willows that were the subjects of some of his most iconic paintings.

An icy lake tucked among jaw-dropping alpine panoramas.

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

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

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

A counter-culture bookstore like no other hides in plain sight in the streets of Paris.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

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

Paris' linguistic guide to the international language of, yes, love.

This massive library holds what was once the largest book collection in the world.

You would never come across this tiny green oasis if you didn't know it existed.

A fantastical bed and breakfast with magically unique rooms.

Most prolific publishing house in the 1600s open to the public.

A 14th-century fortified keep showcases the masterpieces of an ingenious 20th-century clockmaker.

Theme park featuring miniature replicas of European monuments.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

Lavish royal estate punctuated with heated greenhouses.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.