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

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

It's a mystery why these remains were found with no traces of their bodies in sight.

An artificial date palm stands as a memorial to Warsaw's Jewish community.

The church's remarkable frescoes incorporate Finnish artist Hugh Simberg's trademark themes of death and the supernatural.

The pile of books behind the dignified writer gave the statue a most undignified nickname.

The giant statue and its model solar system honor the native Pole who declared that the Earth revolves around the Sun.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

This Czech military museum is home to pink tank that was once a symbol of art and political rebellion.

The oldest garden in Prague, once part of an medieval orchard.

The bones of two medieval royal lions were discovered at the historic fortress.

A lush indoor jungle fills this bustling Madrid transportation hub.

A plaque marks the spot where the saint was shoved off the Charles Bridge and into the river.

This giant crucifix is like U2's Joshua Tree for Swedish death metal fans.

Stockholm's deepest subway station is also a stunning ecological wonder.

The internet as provided by a James Bond villain.

A heated statue pays tribute to one of Sweden's great actresses.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

This legendary dessert was served to Nobel laureates for decades.

A golden plaque marks the site of the mysterious unsolved assassination of the former Swedish prime minister.

Now a hotel, this former bank was the site of a robbery that spawned a psychological phenomenon.

The library's graceful rotunda is like a bibliophile's temple.

An illuminated manuscript comprising the life's work of a lone monk, inexplicably decorated with a portrait of Satan himself.

This large copper bolt represents the benchmark for measuring sea levels in most of Europe.