On any given day this sprawling market houses literally tons of government-regulated gold, gems, and precious metals.

A preposterously luxurious hotel with gold-plated iPads, Rolls Royce chauffeurs, and a staff that trains by watching "Downton Abbey."

Whitewashed mosque contains the world's largest carpet.

Planned as the world’s first zero-carbon city, it had lofty ideals—but is only 5 percent completed and aiming for 50 percent carbon-neutral.

This beautifully restored fortification kept the city safe for centuries.

The building is a gigantic piece of art inspired by the shape of a desert rose.

A marvel of Byzantine engineering under the streets of Istanbul.

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

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

This small-town opera house has appeared much more in national culture and history than its charming setting might suggest.

The study has wall paneling from a 17th century ship.

Where a brain, a beauty, a jock, a rebel, and a recluse met one Saturday and changed their lives forever.

Its eclectic exhibits range from the world’s first motorcycle to Luke Skywalker’s Land Speeder.

To find the "unicorns of the deep" you've got to go downstairs.

World's second largest particle accelerator, where nature reveals its secrets.

When you visit his grave, be sure to rub the Great Emancipator's nose for good luck.

This sprawling mini-golf empire is an impressive testament to a disappearing attraction.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

Thousands of pieces of art have been carved into the rock at the site of an ancient volcanic eruption.

The official atomic museum of the United States explores the explosive and productive history of a much maligned energy source.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.