This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

A marvel of Byzantine engineering under the streets of Istanbul.

A plaque on the base of this statue holds a bewitching design.

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

Seeing her husband shot, she took up his banner and rallied the troops to attack repulsing the enemy with the cry, "Those with honor, follow me!"

Legends surround this jagged rock formation in the New Mexico desert.

This unique shop is full of memento mori art, antique medical equipment, secret society paraphernalia, and historical relics.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Life-sized sculpture of a blue whale made of hand-recycled plastic trash.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

This rare example of a "tidefall" is a spectacular drop from the cliffs down onto the beach.

The 340-year-old house that inspired the classic Nathaniel Hawthorne novel.

These aggressively sustainable art homes look like something out of 1970's science fiction.

These Pre-Columbian petroglyphs contain representations of birds, deer, hunters, and even some early Native flute players.

A multi-storied adobe complex has been inhabited for more than a thousand years.

The tea room that pushed the boundaries of adorable straight into... we can't find the words.

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

New Orleans' famous cemetery, located on the site of a former race track.

A once-booming Mississippi River town with a history of racial violence is now eerie and mostly abandoned.

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

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

This fast-food outlet is the only space and UFO-themed McDonalds in the world.