Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

Polish luminaries and masterful folk art find sanctuary in this unique cemetery.

Open-air museum with a large collection of Soviet-era statues.

The former Nazi Germany concentration camp stands as a museum to remember this dark chapter in European history.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

It houses the remains of a 17th-century version of the Titanic.

A memorial to the murdered Jews of Kaunas.

A narrow strip of land is home to the tallest migrating dunes in Europe.

A cathedral resurrected from the ashes of one of Europe's greatest urban fires.

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

Flamboyant architecture from the turn of 20th century.

3,000 market stands in five former Zeppelin hangars.

A black cat protests the City Guild in Riga's Old Town.

This historic Benedictine monastery brews a booze so toxic that it has often been blamed almost singularly for Scottish hooliganism.

Flaming barrels of tar race through these village streets on Bonfire Night, a tradition that dates back centuries.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Hamburg's first legal sex work is relegated to a gated street that still does not allow pedestrian women.

Old Danish castle immortalized in Shakespeare's Hamlet.

Pre-Nazi swastikas adorn the sculpted pachyderms flanking this brewhouse portal.

Copenhagen's celebrated theme park and gardens.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

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