A beautiful geyser under environmental threat.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

The first declared National Monument in the United States.

Mysterious meeting place for UFO hunters near Area 51.

In the middle of an extremely unforgiving and desolate high desert is the most secret military facility in the world.

A nightmare for the claustrophobic lies hidden in Southeast Asia.

A battle between nature and architecture in the Cambodian jungle.

This historic spot was where America's involvement in the Vietnam War officially came to an end.

Meant to be a lavish presidential home, the palace became a symbol of the fall of South Vietnam.

Witnesses claim the Virgin Mary statue outside the church once mysteriously shed a single tear.

This French colonial post office is arguably the grandest in all of Southeast Asia.

The most famous location in China was home to whole dynasties worth of imperial rulers.

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

The location along the shores of the Great Salt Lake of what was once called, "The Coney Island of the West", now sits barren due to arson and time.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

This geothermal hot spring hides beneath a slowly growing mineral dome.

The largest island on the great salt lake is home to curious creatures and strange stories.

An earthwork sculpture built by Robert Smithson in the Great Salt Lake only reemerges during drought.

This giant ice cream cone is the last remaining icon of a Salt Lake City staple.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

This beloved marketplace mascot poops money and grants good luck.

Dr Barnes' $25 billion private collection of art and arboretum.

The world’s first penitentiary, meant to be humane, drove men insane.