These towering spires and glowing walls are carefully crafted from hundreds of thousands of icicles.

20,000 pieces in a Frank Gehry-designed building.

A Texas cave network is home to some of the world's most spectacular-looking and bizarrely named mineral formations.

35,000 grape hyacinths flow like water down a garden hill.

Nuclear waste dump site now an environmental sanctuary.

A gothic palace of endless stalagmites and pseudoscorpions waits within one of the world's most beautiful caves.

In upstate New York, gorgeous waterfalls and a watermill are slowly being reclaimed by nature.

Life in this isolated, hilltop lighthouse was lonely, but it sure was lovely.

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.

A tunnel of hardened lava along Maui’s famous Road to Hana.

This historic national park is covered in the stunning ruins of red rock pueblos.

The highest point in Washington state is a volcano covered in glaciers.

A humid oasis combines recreation with exploration in a unique underwater cavern.

The second largest waterfall by volume in the U.S., Willamette Falls is outdone only by Niagara in the amount of water that is pushed northward.

The highest dunes in California are the most likely place in the area to hear the Singing Sands.

This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

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

Who needs fancy modern water slides when this giant North Carolina rock works just as well?

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

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

A hollow cement depiction of time's inexorable effect on the human body.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

The drama of nature in full effect in this Nevada State Park.

A French chateau, failed utopian community, odd museum, and Stonehenge replica in rural Washington State.