Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.

Oldest Museum of the Netherlands is a true cabinet of curiosities.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.

The last bastion of Roman presence north of the Alps looms over a German town.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

Tiny castle in the middle of the Rhine made you pay to pass.

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

The prototype for all Nazi concentration camps.

This magnificent museum claims to house the cranium of a disciple and the skull of a pope.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

The footprint of a frustrated devil in Munich's Cathedral.

The fairy tale castle of the "fairy-tale king."

Two stone columns flank the grand Venice square, but there were supposed to be three.

Go inside to really appreciate this 500-year-old technological masterpiece.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

Hundreds of hidden passageways weave through the old quarters of Lyon.

This city square dates back to the Scottish Enlightenment and was home to some of Scotland's brightest minds.

This site contains overlapping ancient graveyards that existed about 1,000 years apart.

This tiny weathered plot is one of the oldest Jewish cemeteries in Scotland.

The building where Mary, Queen of Scots was said to have bathed in white wine.

Edinburgh's oldest statue hides within a parking lot behind the city's iconic cathedral.

The Scottish Reformation leader's grave was paved over and is now a parking lot.

A close look reveals that the Scottish monument is just slightly off-kilter.