A stunning Victorian abbey and walled garden on a lakefront.

This beautiful site is where the first transatlantic telegraph was sent from.

Traveling this mountain pass reveals quaint stone buildings, stunning Irish scenery, and a bridge said to grant wishes.

This ancient Irish tower could easily have stood in for Rapunzel's prison.

This single room has survived the centuries with almost no deterioration.

This controversial Irish show cave is home to a massive formation known as the Great Stalactite.

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

Where commuters walk through remnants of an ancient Greek necropolis.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

An ancient octagonal weather station named for the eight Greek gods of wind.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

This centuries-old rooster survived a devastating fire.

A king's bloodstained shirt is among the gruesome collection of artifacts displayed below Stockholm's Royal Palace.

The world's biggest floating museum in Gothenburg, Sweden.

Stockholm's narrowest alley is barely over two feet wide.

The discovery of an old wall led to the creation of this fascinating museum about the city in the Middle Ages.

Stockholm's tiniest statue is of a small boy looking at the Moon.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

This chimerical bridge/tunnel appears to dead end right into the sea.

Sweden's "good old days" painstakingly re-created in a model village.

It houses the remains of a 17th-century version of the Titanic.

Polish luminaries and masterful folk art find sanctuary in this unique cemetery.

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

An underground city of salt.