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

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

The house where the writer spent his formative years.

A nun spent 16 years painting the stunning Celtic mural that covers the interior of this WWI memorial.

Dublin's "Dead Zoo" serves as a window to Victorian museum design.

An automaton perched above an classic clock and watch store

This postmodern apartment block was designed to be a vertical neighborhood.

Just like in Hollywood, Madrid has also a forgotten walk of fame.

This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.

The little church's beautifully frescoed ceiling has earned it the nickname “the Sistine Chapel of Madrid.”

The only urban monument in the world designed by the great surrealist painter Salvador Dalí.

A lush indoor jungle fills this bustling Madrid transportation hub.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

Head underground and take a tour of the city's working sewer system, and see the underground river Senne, which defined Brussels for centuries before being covered in the 19th century.

Fall down the rabbit hole into a surreal journey of human consciousness "from ass to soul."

Started as a kitchen garden, now the second largest botanical garden in the world.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

An eerie, derelict amusement park in Berlin.

Two monstrous faces loom over a village in Czechia.

Europe's second largest ossuary wasn't discovered until 2001.

This artificial cave looks like something out of a fairytale.

Underneath this small church are 15,000 bones, arranged by an obsessive academic.

Mummified monks and the accidentally interred, in a 17th-century crypt.