This bike path was sunk below water level for maximum wonder.

Some 80,000 Delft Blue tiles line the inside of this Amsterdam walkway.

A ruined castle stands atop a hill surrounded by dragon lore.

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

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

Baroque celebration of the end of the Great Plague of Vienna.

A spherical "micro-nation" in the heart of Vienna.

Swarovski's museum/theme park is a fake diamond fantasia overlooked by a giant.

Walk inside a half mile long crevice right outside the town of Garmisch Partenkirchen.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

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

A Belgian self-built tower inspired by the Bible and ancient civilizations.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A winding path built in secret on the edge of the continent.

A huge musical instrument played by the ocean.

The "stairway to heaven" lookout tower was built to resist weather, arson, and the laws of physics.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

A whimsical bridge uses saxophones to pay tribute to two great men and the European Union.

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

When North America was covered in ice, this was an oasis in the frozen desert.

Try the alligator at this fondue spot, which has been catering to "lovers and hedonists" since 1967.

A rare double mill nestled along the banks of the Aa river.

This concert pavilion on the shore of the Great Salt Lake has been destroyed by fire, water, and disinterest but keeps coming back.

This geothermal hot spring hides beneath a slowly growing mineral dome.