Mysterious 500-year-old tapestries depict a unicorn hunt.

The highest peak in Wales is said to be the final resting place of a giant killed by King Arthur.

A volcanic landmark located on an Ice age lake bed.

A vertically floating hemlock controls the waves and weather at Crater Lake.

Only known mainland rookery of the threatened Stellar sea lion.

The longest continuous lava tube in Oregon.

Officially named the "Loneliest Road in America," this barren stretch of Nevada road offers almost nothing but sky and open fields.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

A charming museum of natural history featuring dioramas and exhibits made entirely by college students.

The United States's largest hand-dug well is topped with a state-of-the-art museum.

The modern birthplace of Irish freedom.

The world's toughest modern Christian pilgrimage leads directly to the gates of Hell.

This short bridge is the only thing connecting a tiny Irish island to the mainland.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

A mining town once rife with murderous disputes over its copious treasures now creates income as a popular spot for photo shoots.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Venice's "Island of the Mad."

An unusual round church in London with a Templar past.

The world's longest known cave system.

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

A reproduction of earth's many biomes.

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

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

A beautiful geyser under environmental threat.