The beautiful baroque library of the Hapsburg empire.

Antiques by the Bay.

A large instrument played by the wind.

A trail weaves through the verses of a poem illustrated by stone sculptures inspired by Native American pictographs.

Rodin's famous depiction of Dante's 'Inferno', amidst a sculpture garden of many of his other works.

The world's first permanently occupied mountain-top observatory continues to report on the stars.

An ominous concrete cube cuts a dystopian silhouette atop this California mountain.

A mysterious monument covered in a binary code marks the heart of tech.

A life-sized mammoth sculpture marks the spot where the remains of a Columbian mammoth were discovered in 2005.

A plaque outside the San Jose airport commemorates the insect's arrival to the West Coast.

The oldest house in the capital of Silicon Valley.

It is locally loved and ridiculed for literally looking like poop.

Three plaques mark the spot where the "forgotten father of broadcasting" worked.

The topiary maze at the Habsburg hunting lodge.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

Also known as the Blue Church, the building was consecrated to the daughter of Andrew II.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

19th-century operating theatre in which the use of ether was first demonstrated - plus, a skeleton and a mummy!

An alley covered with 20 years of bubble gum.

A deserted hodgepodge of experimental structures designed by nearby university students.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

This innovative steam machine was no doubt the most famous of the pioneer locomotives.