200-foot-high minaret and only remnant of Afghanistan's lost city of the Turquoise Mountain.

The Avenue of Mausolea is a series of grand palatial tombs.

This "tower of death" has acted as an observatory, a religious hub, and an executioner's lair.

The 953 windows undoubtedly make this the world's most beautiful screened porch.

Rock-cut cave complex filled with ancient Buddhist artwork.

Unique pagan culture in three extremely remote mountain valleys.

Underground monastery and fortress.

What might be the largest completely Jewish town in the world outside of Israel now faces dwindling numbers and empty streets.

A geological oddity topped with a 2,000-year-old pagan temple.

This series of Armenian caves held the oldest brain, shoe, and winery in the world.

Right up until the 20th century this network of man-made caves was the biggest village in Eastern Armenia.

The convergence of two currents makes this a surprisingly pleasant getaway in the Arctic Circle.

Known as the most dangerous bridge in the world, the Hussaini Hanging Bridge is only one of many precarious rope bridges in Northern Pakistan.

Unusual, mushroom-like rock formations caused by weathering and water erosion, set to disappear, according to geologists.

Extremely isolated Silk Road caravanserai in the middle of nowhere.

Putrefaction plateaus in Iran, where the dead were sent for decontamination before going to their final resting place.

Human ancestor’s 3.6 million year-old footprints.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

Rippling sand dunes frozen in the Arizona rock.

Remnants of successive wars and Muslim colonialism in the 11th century.

Hell on Earth is actually a small town in Michigan where anyone can be mayor for a day.

A speakeasy takes on Chicago's drinking culture.

Former bath house turns gastropub.

The massive cave church of Cairo's Zabbaleen community is one of the largest Christian churches in the Middle East.