The Pantheon is a 2,000-year-old temple with a dark secret. Today, using cutting-edge archaeological methods and brand-new evidence, experts look beneath the streets of Rome to find out why it was built and how it survived so long.

Experts investigate myths of a secret portal to hell in Hierapolis.

Experts travel inside ancient mounds to investigate the legend of Midas.

Scientists use pioneering technology to discover the foundations of Venice.

The Tower of London is a centuries-old castle shrouded in a grisly past.

A prehistoric structure could reveal mysteries to the Bronze Age.

Experts explore sunken ruins and reveal one of the first great empires.

Experts decode an Egyptian pyramid constructed as if it floats on water.

Deep in the Iraqi desert, the world's only ziggurat towers over the remains of the first civilization ever known in human history; armed with pioneering satellite imagery, experts investigate the dark mysteries behind this massive, ancient structure.