The silly symbol for an underground protest group is now scattered around the city.

A mysterious structure left behind on the Polish mountainside, sometimes called "Hitler's Stonehenge".

Order “Proletariat’s Cutlet” at this communist-themed restaurant allegedly once visited by Lenin.

This imposing 20th-century castle was abandoned before it was ever completed.

These massive moving sand dunes have swallowed an entire village and are still on the run.

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

The site of the first battle of World War II.

Countless stories attempt to explain Poland's mysterious J-shaped trees.

Designed to commemorate the king's coronation.

Fantastic stainless steel dragon gates complete with mesh wings.

The enchanting archway is the only surviving portal into Dublin's lost medieval wall.

A museum that cashes in on its infamous little people while teaching you a thing or two about the Irish fey.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

This seaside pine grove features an exclusive watchtower that presents amazing views.

This abandoned beacon is moving closer and closer to the sea.

This remote sandstone cliff has one of the richest collections of Livonian petroglyph marks.

This enigmatic artifact remained buried in a churchyard for years.

These abandoned vessels are destined to be reclaimed by the forest.

A creepy statue of a hooded ghost hauls itself up from the water in a historic Lithuanian city.

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

Museum deep in the catacombs of St. Michael the Archangel Church is explored by touch, sound, and smell.

Legend says lovers who hold hands while venturing along this stone jetty and kiss at the end will remain together forever.

The widest natural waterfall in Estonia is a sight to see in all seasons.

This stunning limestone waterfall is the highest in Estonia.