The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

This now abandoned restaurant provides some of the most amazing views of Lisboa.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

Houses are tucked between, on, and underneath giant boulders.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

A stately palace has been converted into the world's largest cannabis museum.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

A house covered entirely with shells.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

An abandoned jewel of a ballroom on the top floor of Australia’s busiest rail station echoes with the sounds of a bygone era.

An abandoned Art Deco hotel nestled on the side of a wooded mountain.

An eerie, derelict amusement park in Berlin.

A giant sculpture of the legendary "Salmon of Knowledge" celebrates the return of fish to Belfast's River Lagan.

These barriers stand as stark reminders of Northern Ireland's troubled past.

Though they've since been renamed, these two streets hint at Dublin's darker days.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.