This declassified Cold War bunker hosts a large collection of Swedish aircraft.

A monumental magenta installation looms over a tangle of roads and tracks, as controversial as it is conspicuous.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

A patriotic medieval knight in driven-nail armor raised money for widows and orphans of WWI.

Royals, rebels, and artists have all conversed at this grand 19th-century Viennese coffee house.

A mechanical clock built in 1914, with a rotation of 12 historical figures on its face.

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

One of Ireland's most infamous prisons for rebels including men, women and children.

There's something in the air as history repeats itself at this museum dedicated to the Swedish pop band.

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

One of the best-preserved medieval streets in Europe.

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

Experience what life was like in Ireland during the Viking and medieval ages.

These murals stand as reminders to the troubled history of this Northern Ireland city.

The ship built to ferry passengers and goods to the doomed Titanic is now the last remaining White Star Line vessel.

A contemporary art installation housed within a Gothic cathedral.

A memorial in the Tiergarten is a reminder of the suffering inflicted on homosexuals by the Nazi regime.

One of the world's heaviest musical instruments towers within a popular urban park.

A brush maker used his factory to protect blind Jews from the Gestapo.

When German-Iraqi relations broke down, this embassy was vacated post haste.

Berliners converted a bombed-out, disused lot into a community-run urban farm with its own cafe and bar.

Reminders of the Battle of Berlin still scar the railway.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

This museum is home to a sugar sculpture of the Berlin Airlift Memorial.