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

This unusual lava tube spouts seawater during high surf.

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

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

A Hawaiian stairway to heaven—that you can't climb.

This former luxury resort in Kaua'i is now an abandoned relic.

This blowhole is supposedly caused by a trapped monster.

An authentic replica of an Asian temple and garden hidden amongst the natural beauty of Hawai'i.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

The oldest operating pharmacy in the world features 800-year-old recipes.

This Roman statue is missing a limb from when the Venetians stole it from Constantinople during the Crusades.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

The only museum with its curator—and her pets—buried inside.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

Outlaws, hot springs, and tragedy have all left their mark on this ancient road in the Icelandic highlands.

A lonely beacon, precariously perched atop a remote sliver of rock.

This tumultuous Icelandic lava field looks so alien European researchers want to use it as a stand-in for Mars.

A sulfuric martian landscape that looks far better than it smells.

This replica Viking village was created for a film that was never shot and is now open to visitors.

These ominous lava formations were said to be an entrance to the netherworld so of course they inspired a famous metal band.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.