The glowing blue Nymphaeum of Emperor Tiberius.

Pompeii's less famous neighbor is still revealing her secrets.

A sulfuric hellscape in southern Italy.

A submerged archeological park still holds the wonders of a Roman Sodom.

Virgil's many-mouthed gateway to the underworld.

270 million year-old forest of stone.

The small cliffside monastery known as the Tiger's Nest is said to be the meditation site of an eighth-century Buddhist master.

Legend holds eating just one of these black eggs can add seven years to one's life.

Hot springs monkey spa in the middle of Hell's Valley.

One of the world's largest salt caves is filled with fragile salt sculptures, salt rivers, and huge salt megadomes.

Hydraulic systems in an ancient underground Iranian city.

The palace of the King of Kings, burned by Alexander the Great.

An Aztec snake god has taken the material form of an apartment complex.

The largest wine cellar in the world is a 150-mile network of underground caves near the capital of Moldova.

A forgotten remnant of the Soviet Union, Transnistria is an unrecognized country hidden behind a heavily militarized border between Moldova and Ukraine.

A salty red wasteland in Tanzania is a breeding spot for endangered flamingos.

Stunning wetlands ablaze with pink lotus flowers.

Ruins of a German Castle on top of a towering stone pillar.

Five mile wide circular ring of rock in the Russian Far East is a curious geological oddity.

This attraction was abandoned after the Chernobyl disaster.

Sculpture that doubles as a time capsule so that life can survive radiation outside Chernobyl.

This beautiful natural train tunnel is said to grant the wishes of visiting lovebirds.