A clumsy-looking flying locomotive rusts within sight of a busy rail station.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

This elaborate towering structure was once famed for its revolutionary height.

Yo, Adrian!

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.

This medieval Italian town is a sheer (and beautiful) cliffside defense.

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

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

The world’s first penitentiary, meant to be humane, drove men insane.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

In a city that boasts four separate inclined cable railways, this is one of the busiest funicular lines in the world.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

Italy's "New Mountain" rose from the ground in a volcanic eruption in 1538.

Virgil's many-mouthed gateway to the underworld.

A tree that defies gravity grows in an ancient ruin.

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

This one-time health resort was used by aristocrats around the world.