Medicinal spa created with the discharge from a geothermal energy plant.

Elaborate tile work in this railway station tells the story of Portugal.

A vast Communist-era exhibition space in the Bulgarian capital.

A striking symbol of the Bulgarian capital.

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

This hill made entirely of ancient Roman jars was simply a garbage dump to the people of the time.

The final resting place of the poets Shelley and Keats.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

2300-year-old Roman road connecting the empire.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

The ruins of an abandoned medieval city where the last Byzantine emperor was crowned.

This legendary city has been a tourist attraction for centuries.

The historic tower houses of this nearly abandoned Greek town have been compared to the spikes on an iguana's back.

For nearly 2,000 years this church has been waging war on local snakes by importing cats.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

A closed London rail station created to cart away the dead still bears the marks of attempts to make it less morbid.

A Victorian natural history and ethnographic museum with wonderful turn-of-the-century, science-book-esque evolution displays.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

Eighty million natural history specimens call this gargantuan museum home.

The anatomical-pathological collection of a man who changed surgery.

The largest of London's subterranean rivers and once a mad, bad center of London life.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.