Mile-long cave system near Great Smoky Mountains.

An ancient cave system in Tennessee’s Appalachian foothills converted to a 1,200-person music venue.

This mansion turned restaurant was once a pitstop for Al Capone during his travels.

This narrow coastline trail through the dense Kauai wilderness is among the most beautiful and dangerous in the world.

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.

Submerged lava formations create incredible waterworks.

This blowhole is supposedly caused by a trapped monster.

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

Race through the maze, get your name on the sign.

A unique set of caves that spits waves back out into the ocean.

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

The southernmost point in the United States is a beautiful place to look at but a deadly place to wade in.

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

A beach made of semi-precious green sand on the Big Island of Hawai'i.

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

Watch the newest land on the planet form before your eyes.

This black shoreline is made up of exploded lava particles.

A true treehouse near Hawai'i Volcanoes National Park.

A priest with no formal artistic training used basic house paint to create gorgeous religious scenes inside this historic church.

Try your hand at old-fashioned coffee growing at this museum devoted to one of the world's most coveted beans.

This unusual lava tube spouts seawater during high surf.

This legendary urban waterfall creates a dazzling display of rainbows.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.