Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

This 14th century wine cellar is home to the oldest barrel-stored wine in the world.

A towering baroque basilica jutting out of the French countryside.

This striking fort on the Maginot Line looks just as it did after being destroyed in the Fall of France.

The remains of 40,000 humans, meticulously stacked in a tiny churchyard shed.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

A surrealist timepiece by the artist of melting clocks.

Site of a classic 19th-century physics experiment to prove the earth is rotating.

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

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

Spiral alpine structure provides an alternative experience of viewing the Matterhorn.

This Swiss cemetery is reserved for people who died in climbing accidents.

The most impressive of Basel's three remaining city gates.

This artistic fountain display pays homage to this area's theatrical history.

An interactive exhibition space dedicated to the kinetic sculptures of Swiss artist Jean Tinguely.

The smallest museum in Basel, Switzerland, is a two-foot-by-two-foot window in the door of a 600-year-old house.

One of the world's largest collections of pharmaceutical artifacts.

A nearly 500-year-old sculpture depicts a man eating a sack of babies, and no one is sure why.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

A 600-year-old elm tree with a built-in seat and thatched roof.

A lasting testament to the Klondike Gold Rush.