This massive mural by famed pop-artist Keith Haring was hidden for almost 30 years until its 2018 rediscovery.

Colorful and chaotic stacked hotel in North Holland.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

Created as a "model concentration camp" to hide Nazi atrocities from the international community, this former camp-ghetto now holds a museum and memorial honoring the lives lost within.

A peculiar clock commemorates a historic victory won by ringing the noonday bell an hour early.

A former top secret nuclear fallout shelter now operates like a hotel stuck in the Cold War.

Throughout this shopping mall are medieval ruins that were discovered during the mall's construction.

This unusually shaped mountaintop tower looks like a UFO floating over the city.

Increasingly decayed figures stand as a powerful reminder of the human costs of Czech Communism.

Looming communist pillar with a Czech twist.

This spooky statue sits outside a famous Prague theater.

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.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

What looks like a suicide in progress is actually a statue of Sigmund Freud.

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

A church of bones, decorated with 40,000 human skeletons.

Macabre astrological automaton clock dating to the late 1400s.

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

The second-highest train station in Europe.

Lucerne's central prison was converted into a tourist hotel with a bare minimum of changes.

Swiss vineyards in a UNESCO heritage site.

A historic observatory precariously perched at the "Top of Europe."

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.