These mechanical goats first battled it out in the year 1551, all because of an overcooked deer.

An impressive monument to Poland's independence.

The site of the first battle of World War II.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

The palace window through which Protestant nobles flung two Catholic regents, thus sparking the Thirty Years' War.

Old Danish castle immortalized in Shakespeare's Hamlet.

A little sculpture with a large wardrobe.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

Eat the ultimate iteration of Portugal's most beloved pastry.

Perhaps the most spectacular grotto along the Algarve coastline.

This mountaintop observatory is home to one of the world's largest reflective telescopes.

The four landings commemorate a royal visit to Europe's biggest observatory.

The world's largest single-aperture telescope resides in the Canary Islands.

These wooden balconies that are both decorative and functional.

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

This bridge was constructed from the rubble of the infamous Bastille.

The celebrated eyesore created by starry-eyed sweethearts.

The narrowest street in Paris.

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

This modest marker near Notre Dame identifies the very center of Paris.

This demon atop the Notre-Dame de Paris looks utterly bored.

The location of this small park was once the site of an infamous public morgue.

This recessed garden protects thousands of mountain plants by creating its own microclimates.