These plaques found across Warsaw commemorate the sites where executions or battles took place during the German occupation.

A memorial to the beloved brown bear that served in the Polish army during World War II.

An Orwellian sculpture with eyeball cameras watches passersby.

The hidden lair of an alchemist rediscovered in a 2002 flood.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

A saintly relic hidden in a Prague church basement.

A steampunk-styled three-floor factory churning out art, activism, and electronic beats.

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

The medieval "Bearded Man" relief still serves as a clever flood warning marker.

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

This Ottoman-era church is hidden amid a busy tourist area.

When construction began on this hotel, developers were surprised to find the ruins of an ancient civilization.

A man's head is enshrined beneath a statue near the first building constructed for the modern Olympic Games.

The oldest standing Byzantine church in Athens is tucked within a monastery in the middle of an upscale shopping district.

The largest coin pyramid in the world is a carefully balanced stack of over 1,000,000 pieces.

This former KGB building is now a museum memorializing the people who suffered during the Soviet regime.

The statue of a legendary giant who carried Christ and shouldered the world's sins.

Latvia's symbolic mountain-shaped national library is home to millions of cultural tomes.

A 300-kilogram egg sculpture that embodied a neighborhood revival.

This pair of gilded girls atop an Art Deco building in Copenhagen were built to function as a weather indicator.

This ordinary street was made infamous by a legendary visit from the devil.

An ultra-modern diversity park in Denmark has turned an entire city block electric pink.

A Byzantine church containing the holy remnants of three saints sits atop the site of an ancient temple.

The ruins of an ancient Roman tomb hidden in the basement of a trendy clothing store.