Welded sphere dropped from space.

A marvel of Byzantine engineering under the streets of Istanbul.

No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

A massive collection of petroglyphs dating back some 40,000 years.

Home to nearly a third of the world's mud volcanoes, Azerbaijan is home to a messy, bubbling, and sometimes explosive landscape.

Resonant stone, that has been played since prehistoric times.

A quirky house created entirely out of glass bottles combines a collector's spirit with an artist's flair.

In the foothills of the lesser Caucasus, a centuries-old fortress still stands.

A shrine of fire worship built on top of a natural flame.

The building's fluid, wavelike walls are a true feat of architectural ingenuity.

A unique museum dedicated to culture and artistry of carpet weaving.

This mysterious but iconic tapered tower appears in many Azeri fairytales and legends.

A gigantic collection of teeny, tiny books.

Mysterious hillside with a continuously burning natural fire.

The village's cobblestone streets are lined with shops displaying exquisite copper craftsmanship.

Foreign invaders almost left this lovely Caucasus palace alone—almost.