The telescope that discovered Neptune.

A historic steam train meanders along one of the most scenic rail routes in Germany's Black Forest.

Legendary site where an evil bishop was devoured by rodents.

The real life town from the Pied Piper of Hamelin has a mechanical puppet show that retells the famous story many times a day.

Four-story slides send people whizzing through the math department at this Munich university.

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

A Nazi concentration camp and Anne Frank's place of death.

Model Trains and Much More in Hamburg.

Cold war icon and onetime "hole" in the iron curtain.

The great Danube river starts here.

A 12th-century fortress containing some of Berlin's oldest buildings.

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

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

Started as a kitchen garden, now the second largest botanical garden in the world.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

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

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

Venice's island of the dead.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

The first botanical garden, a feather in the cap of the Grand Duke of Tuscany.

Fortified medieval tower house with lovely roof garden.

The bomb-ravaged remains of of a colossal Neptune.

Five candy-colored villages on the Italian Riviera.

The world's most active stratovolcano is almost always erupting.