An enigmatic monument to the Irish revolutionary who plotted an uprising against British rule.

This 18th-century fort surrounded by a moat was used to store gun powder and ammunition, and now sits in the middle of a large part in Dublin.

After it was swallowed by a Georgian mansion, this medieval castle remained forgotten for centuries.

A series of stained glass artworks that depict images of the hit TV show.

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

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

This massive monument has been telling the time for 150 years—at a slight angle.

The only monument to name all of the passengers and crew who died on the RMS Titanic.

Northern Ireland's Brobdingnagian stepping stones.

This tiny train shuttles passengers to one of Northern Ireland's most spectacular sights.

This impressive chasm is one of the longest natural underground cavities in the world.

A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

A medieval church with largest and oldest collection of Renaissance frescoes in France.

Historic medieval fortified city in southwest France.

Defy gravity at this fascinating Pyrenees overlook platform.