Successful artist residence program has filled this ranch with dozens of sculptures over the years.

Neither Spanish settlers nor anyone since has been able to tell who built these strange California rock walls.

A Roman-inspired temple once controlled half of San Francisco's waters.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

This surreal-looking tree pruned more than 1,000 years ago is still producing olives for oil.

This metal tower in the desert provides views of a handful of Nazca geoglyphs.

This medieval manor house was equipped with secret compartments for hiding priests.

Scotland still bears an enormous scar of its Roman past.

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

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

Each time a baby is born in Ghent, these streetlights flash in silent celebration.

A Museum of Psychiatry in a still-operating mental institution.

Housing the groundbreaking maps and globes of Gerard Mercator.

This isolated island is often capped by its own fluffy cloud.

Aliens and monsters lurk inside this museum dedicated to one man's lifelong adoration of all things sci-fi.

A Swiss board game museum housed inside a picture-perfect castle.

This maze-like slot canyon is a unique gem within an already fascinating geological area.

This breathtaking monastery was established by Saint Benedict himself 1,500 years ago.

This abandoned boat was left in place thanks to its rotting beauty.

The only diamond mine in the world where you can keep what you find.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

A celebrity from the late Cretaceous period.

The highest tides in the world come in and out here twice a day, allowing you to essentially walk along the ocean floor.

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.