This grand manse has been transformed into a museum devoted to one of the founders of Fantastic Realism.

The solemn exterior conceals an opulent interior of this 17th century church.

A rooftop restaurant hides in plain sight atop Vienna's Palace of Justice.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

Apartment complexes built into huge repurposed natural gas tanks.

Legends surround an ancient tree trunk riddled with nails for good luck.

This cubist Vienna church building looks like some sort of alien stonehenge.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

A spherical "micro-nation" in the heart of Vienna.

England's most famous front door has an accidental doppelganger.

A pagan tradition of draping trees with rags eerily lives on.

This seaside production studio was built to film 'Titanic' and has been the wet set of choice for other Hollywood productions since.

This suburban British town holds secrets that would have made the druids proud.

There are thousands of tributes and memorials to the King, but none quite like this one in a Kraków city park.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

Poland's oldest surviving university building holds a wealth of historic science instruments including some used by Copernicus.

This man-made mound monument was built out of soil from all across the Polish empire.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

Real bones which are said to have belonged to a Polish dragon.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

Installed at a chaotic intersection, this gave London traffic cops a place to hang their heavy woolen coats.

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

A relic of Victorian grandeur hides beneath a busy South London road.

Lovers proclaim their unbreakable bond by leaving their names on locks fastened onto the Shoreditch fence in East London.