The glowing blue Nymphaeum of Emperor Tiberius.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

A 16th-century horror show built in a lovely Italian garden.

Rippling sand dunes frozen in the Arizona rock.

Dramatic river bend surrounds a natural red-rocked pedestal.

Most-visited and most-photographed slot canyon in the American Southwest.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

Limestone caves with spectacular showcase chambers.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

Little island known for its massive beachfront "flowerpot" pillars.

Remote, volcanic island that Darwin, Hooker, and the Royal Navy shaped into a thriving, artificial ecosystem.

An island in the middle of a lake, in the middle of a volcano, in the middle of a bigger lake, in the middle of a bigger island, in an archipelago, in the Pacific Ocean.

An island made out of shells, including a cemetery.

Smooth basaltic rocks tell a tale of ancient glacial waterfalls.

See massive fossils that are over 200 million years old in northeastern Arizona.

These azure waters were thought to lead to the Mayan Underworld.

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

Dig for your own trilobites in this goldmine of invertebrates.

Prehistoric animals decorate this popular outdoor park.

Cliffs that hold fossils, including the earliest known reptile, dating back more than 300 million years.