A small etching on the white marble parapet was written in runic script by a Viking mercenary.

A marvel of Byzantine engineering under the streets of Istanbul.

A striking symbol of the Bulgarian capital.

An underground city of salt.

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

The Polish capital has had a deep connection to its guardian mermaid for almost a millennium now.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

Steadily reminding Czechia of its past.

Looming communist pillar with a Czech twist.

A turn of the century building boasting some of the most beautiful art nouveau architecture in Prague.

A series of playful yellow penguins share a serious message about the environment.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Walk through Czech history in Prague's largest graveyard.

Countless grotesque faces stare out from this eerie Prague art wall.

Macabre astrological automaton clock dating to the late 1400s.

This quaint museum tells about more than just the birth of Jesus: "betlémy" are an important piece of Czech history.

Be(w)ar(e) the moat around this historic Czech castle.

An enormous and lavish Gothic church in Czechia.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

Baroque celebration of the end of the Great Plague of Vienna.

Op-art architecture designed for happiness.

The topiary maze at the Habsburg hunting lodge.

One of the best-preserved Roman amphitheaters is still used today, but for less brutal events.