A walk through the historic city center, under the streets of Seattle.

Elevated freight railway turned wildly successful urban park.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

A six-ton wedding present for the King of the Scots.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

Near the former site of numerous witch burnings, this lavish Edinburgh mainstay pays homage to Scotland's brutal history.

Protecting the dead from opportunistic body snatchers.

The final resting place of soldiers' loyal canine companions.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

A stunning Victorian abbey and walled garden on a lakefront.

These imposing walls and towers look more like the ruins of a fortress than a monastery.

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

An ancient Egyptian temple in the middle of Madrid, Spain.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

A tiny church on a man-made island in the Adriatic.

A curious little museum dedicated to the furry feline in the cat haven that is Old Town Kotor.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

Stone Age solar temple is aligned with the sun on each equinox and solstice.

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

Giant marble phalluses on the sacred island of antiquity.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.