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

Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.

The castle was reconstructed to fit Kaiser Wilhelm II's romanticized vision of the Middle Ages.

Hundreds of prehistoric stones, arranged in perfect lines in a French field.

The world's largest reflecting pool is just two centimeters deep.

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

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.

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

This irregularly shaped sea fortress has defended not one but three different sovereign states.

An abstract monument to a symphonic composer.

A subterranean house of worship carved right out of the bedrock.

The first monument in Estonia that was made by an Estonian sculptor.

A massive tribute to Estonian history and culture.

The Guardian of Tallinn.

Walk along the medieval fortifications that have been protecting Tallinn since the 14th century.

A spectacular Petrine Baroque summer palace commissioned for Catherine I by Peter the Great.

Old Danish castle immortalized in Shakespeare's Hamlet.

Climb to the top of its spiral spire for spectacular views of Copenhagen.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Copenhagen's celebrated theme park and gardens.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

This spooky statue sits outside a famous Prague theater.

A mocking tribute to the past and modern leadership of Prague.