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

The former Nazi Germany concentration camp stands as a museum to remember this dark chapter in European history.

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

Deep in a Polish forest, this collection of Iron Age megaliths still holds onto many of its ancient secrets.

What was once an underground Nazi city is now Europe's largest bat reserve.

A peculiar family mausoleum built by a German nobleman captivated by the occult.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

This 700-year-old structure is one of the most unique architectural and historic monuments in Gdańsk.

The site of the first battle of World War II.

This antique thermometer honors the creator of the first universal temperature scale.

Modern art commemorates one of the first military actions of World War II.

A merchant court dedicated to the fictitious King Arthur is heavily adorned with bizarre Renaissance art.

Described as one of the Baltic region’s most daring and original construction projects.

This lonely Lithuanian chapel looks more beautiful and haunting in decline than it ever did in life.

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

The first museum dedicated to exploring humanity's cultural relationship with the celestial world.

This magnificent Art Deco church is a reflection of Lithuania’s turbulent history.

While this monument tile is shrouded in mystery it also marks the end of the longest ever human chain.

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

An abandoned masterpiece of Soviet Brutalist architecture.

A small monument in Lithuania marks the geographic center of Europe—or at least one of the claimants.

Launch site for nuclear war against Western Europe.

Legend has it that Napoleon Bonaparte fell in love with this Gothic church.

Travelers who fall victim to this mermaid's charms are destined to stay in Užupis forever.