An opal mining town in the middle of Australia where people live, worship, and shop underground.

This gracefully curving formation looks like a massive wave that was suddenly turned to stone.

Beneath the southern end of the Golden Gate Bridge is the “Gibraltar of the West Coast,” a fort built to protect the San Francisco Bay from naval attack.

The century-old bell and clock tower at UC Berkeley is the third-tallest in the world, and has fossils.

One of Hawaiʻi’s most notable historic petroglyph fields lies within a major resort.

One of Hawaiʻi’s largest petroglyph fields contains a number of depictions of people.

In 2018, Pohoiki Road was severed by lava flowing from the eruption of Kilauea.

Hawai'i Volcanoes National Park is home to one of Polynesia’s largest petroglyph fields.

A controversial memorial at the place where Captain Cook met his violent end.

The famous aviator's final resting place is a study in natural beauty.

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

Memorial to the first European to set foot on Maui.

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

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

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

An historic, one-lane, pedestrian suspension bridge on Kauai.

This blowhole is supposedly caused by a trapped monster.

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

Millions of years of oxidation make a drive down this winding Death Valley road surprisingly colorful.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

"Only the devil could play golf here."

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.