The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

Millions of years of oxidation make a drive down this winding Death Valley road surprisingly colorful.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

See massive fossils that are over 200 million years old in northeastern Arizona.

The largest self-built castle in the U.S., six decades in the making.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

Odd outsider art installations surround a Gold Rush-era ghost town.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

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.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

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

The celebrated eyesore created by starry-eyed sweethearts.

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

A hugely vast Irish landscape of barren rock that stretches for miles.

One of Ireland's most infamous prisons for rebels including men, women and children.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The modern birthplace of Irish freedom.

Amidst the bustling streets of Dublin, there is a hushed garden that is dedicated to "All those who gave their lives in the cause of Irish Freedom."

Fascinating town where normal life interfaces with the occult.

Famously misunderstood wonder of the ancient world

The oldest working mechanical clock in the world.

The National Railway Museum in York is the largest railway museum in the world, attracting almost 1 million visitors per year.