Seat of the Duke and Duchess of Devonshire for centuries.

A magnificent winding road through a steep valley, with deep natural caverns at the bottom

A gorge full of caverns where early humans lived alongside cave hyenas, giant mammoths and wooly rhinoceroses.

In the past, Renaissance sex workers were encouraged to entice customers on this bridge.

Two stone columns flank the grand Venice square, but there were supposed to be three.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

Go inside to really appreciate this 500-year-old technological masterpiece.

This Italian-style temple replica has been threatening to fall off the Irish coast for hundreds of years.

These engineering masterpieces are a dominant feature of the Belfast skyline.

It was once nicknamed "the most bombed hotel in Europe."

A giant sculpture of the legendary "Salmon of Knowledge" celebrates the return of fish to Belfast's River Lagan.

A palatial former bank building now houses what may be the poshest art venue (and former Tesco) in Belfast.

The ship built to ferry passengers and goods to the doomed Titanic is now the last remaining White Star Line vessel.

The statue honors a beloved bird that once roamed St. George's Market.

For part of the year, this innovative greenhouse is painted white to keep the plants from getting scorched.

Step into Narnia at this small park featuring statues from "The Lion, the Witch, and the Wardrobe."

These barriers stand as stark reminders of Northern Ireland's troubled past.

The last Victorian market in Belfast.

Deep in the countryside lie the remains of one of the grandest Roman dwellings in Britain.

Buried next to Pompeii, this lesser-known Roman villa was the opulent vacation home of Emperor Nero's wife.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

Erotic art covers the walls of the largest ancient pleasure palace.

Ancient snack bar of the Roman Empire re-opened.

The walls and streets of the ancient city are peppered with penises.