A cemetery for Slovenian notables also serves as a popular recreation space.

In between two buildings in Ljubljana, medieval tunnel to nowhere.

Slovenia's first mosque is a striking mix of Islamic and modernist architecture.

This bust remembers the haunting local legend of a murderous monk.

This stunningly massive housing complex is a go-to filming location for dystopian sci-fi cinema.

A trough of 700 strange bronze faces runs through a narrow alley in Ljubljana's old town.

A public work of art that also provides some relief from the summer heat.

A whimsical bridge adorned with decorative dragons.

The kitsch mansion of the former Romanian president Nicolae Ceaușescu features a golden bathroom.

Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

This metro station doubles as an unintentional paleontology museum.

The bust of Romania’s most notorious ruler, Vlad Dracula aka "Vlad the Impaler," keeps watch over the ruins of his medieval court.

This once-derelict building is now one of the most beautiful bookstores in the world.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

Romania's triumphal arch looks out over Bucharest.

Lavish royal estate punctuated with heated greenhouses.

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

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

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

For hundreds of years, automatons moving to metallic music have been marking the passage of time.

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

A doorless and windowless folly in England that evokes curiosity over its mysterious origins.

This small bronze pyramid marks the center of Belgrade, but some say it is a Masonic symbol.

One of London’s rare Tudor-era buildings is a fate-defying gatehouse for a church.