The only visible remains of this ancient Greek underground temple is its roof protruding from the earth.

Also known as the Temple of Poseidon, this is one of the best-preserved Greek temples in the world.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

Ancient snack bar of the Roman Empire re-opened.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

Ruins of a 10th century church tucked away deep in a botanical garden.

A town saturated in Italian rationalist architecture was once marshland drained by Mussolini.

A geothermal energy project gone wrong is fracturing the city's picturesque architecture.

The fairy tale castle of the "fairy-tale king."

This enchanting Victorian estate was home to the world's first hydroelectric power generator.

These upturned herring boats make nifty storage sheds for fishing goods.

This enormous secondhand bookstore inside a Victorian train station sparked the "Keep Calm and Carry On" craze.

This giant wooden treehouse within a sprawling garden has its own eatery.

This iconic 1,000-year-old medieval castle is a favorite of the film industry, most notably as the location for Hogwarts in Harry Potter.

This 13th century castle is chock full of ghosts and impossibly rare cows.

The medieval-looking hammer beam teak roof may be a Victorian vanity, but it's still absolutely magnificent.

This museum honors the young maritime hero who became an unexpected Victorian-era celebrity.

London's marvelous wildfowl reserve along the Thames.

A replica of the steam engine that hauled Queen Victoria's Royal Train is on display at Windsor.

All unmarked mute swans on the Thames are owned by the Queen per a tradition that began in the 12th century.