One of the world’s largest and deepest freshwater springs, where mastodons once roamed.

The so-called "world's shortest river" is actually a window into a cave.

Meet manatees face-to-face at this zoo for native species.

A peaceful, unique botanical garden complete with waterfalls, mini islands, and swans.

The first custom-designed building to showcase the works of Dale Chihuly is a wonderland of glass and light.

A luxuriant botanical garden below sea level.

This beautiful Miami garden was designed as a laboratory for tropical plants.

A hidden beach at the end of a tunnel of mangrove trees.

Where manatees are the snowbird vacationers in these balmy Florida springs.

The only swimming pool listed on the National Register of Historic Places is emptied and refilled each day with naturally filtered water.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

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

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

Football field-sized microalgae production tanks on the Hawaiian coast create a stunning view from space.

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

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

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

Submerged lava formations create incredible waterworks.

This legendary urban waterfall creates a dazzling display of rainbows.

A true treehouse near Hawai'i Volcanoes National Park.

A prehistoric landscape hidden in the cliffs of Maha'ulepu.

A once-glowing grotto at the bottom of Waikapalae Wet Cave.

This industrial area was the dumping ground for massive amounts of trash, some of which washes up as tiny bits of sea glass.

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