Different sections of the Zemun Fortress were built in the 14th and 15th century as a response to the advance of the Ottoman Empire.

This statue of the famed author, actor, and journalist is made entirely of screw-nuts.

A surrealist timepiece by the artist of melting clocks.

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.

The tomb of history's greatest potato promoter is surrounded by tubers.

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

Explore the 500-year history of silk-making in Lyon at this museum, workshop, and boutique.

The first modern cemetery of Lyon is complete with more than 200 chapels and monuments.

A colorful piece of contemporary art cheerfully clashes with Lyon's historical architecture.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

Lyon's miniature version of the Eiffel Tower was built as a statement in support of French secularism.

Hundreds of hidden passageways weave through the old quarters of Lyon.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.

An off-the-beaten-path boutique stuffed with an eclectic collection of upcycled goods.

This scale model of our solar system hid in plain sight for years before a physics team sought out all the planets.

This 135-year-old weather station studied the effects of the climate on human health.

A World War II evacuation tunnel turned into a history display of Croatian state and people.

A small memorial to a deadly night in Serbia that shook the world before it was swept under the rug.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

This giant middle finger statue sends an unambiguous message to Italy's bankers.

This ancient Egyptian obelisk still bears the wounds of World War I.