148 feet long and in the middle of a verdant forest.

Once thought to be the oldest living tree in the world, Methuselah was germinated before the Egyptian pyramids were built.

Ancestral Puebloan ruins, natural arches, and box canyons abound in this seldom-visited corner of Monument Valley Navajo Tribal Park.

One of the oldest living oak trees in the Southeast.

Despite being one of the most photographed vistas in the Rockies these twin peaks are rightfully known as the "Deadly Bells."

The only diamond mine in the world where you can keep what you find.

Sandstone rock formations that look like they belong on the cover of a progressive rock album.

The lush coastal city of Astoria is riddled with forgotten secret sidewalks.

A tiny red pebble marks what may be the quietest outdoor spot in the United States.

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

Visit this playground of waterfalls, caves and sinkholes.

The longest living non-clonal organisms on Earth.

This glamorous old building is said to have inspired the Tower of Terror.

When ecosystems collide in the arid Southwest.

This maze-like slot canyon is a unique gem within an already fascinating geological area.

The eccentric mansion of one the most popular horror authors of modern times.

This lake in the Cascades lives up to its name, disappearing down a hole every spring.

Rare recess caves fill this unbelievably beautiful Ohio park.

The longest navigable underground river in the United States is home to countless blind and albino animals.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

The highest bridge in America was built for an almost unnervingly small amount of money.

European castle ruins in an American state park are actually the product of death and grief.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.