In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

This 1930s log cabin began as a taxidermy museum but is now a popular country music venue.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

A nature and cultural preserve named for its multitude of petroglyphs carved by the Northern Sinagua people.

The highest point in Arizona is an oddly snow-topped peak within the otherwise arid state.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

Many generations of travelers have passed through the steep, smooth walls of this canyon.

Mine your own precious stones.

This unusual lava tube spouts seawater during high surf.

Get up close and personal with these majestic fish.

More than 2,000 species of tropical plants call this nature preserve and sanctuary home.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

A cooled lava flow from the Haleakalā volcano formed these surreal-looking columnar basalt structures.

Images chiseled into the basalt here date back an estimated 300 years.

Take shelter from Hawai'i's tropical heat under the massive canopy of largest Banyan tree on the island.

A series of waterfalls and pools that flow through the 'Ohe'o Gulch and into the ocean.

Ten acres of the Kula Forest Reserve make up this wonderous state park.

Climbing this abandoned railway leads to breathtaking vistas of O‘ahu.

This coastal cavern is associated with the Hawaiian god of creation.

An invitation-only museum of items natural and bizarre, arcane and exotic.

Golden Gate Park's historic collection of plants.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.