An Iron Age fort on the edge of a seaside cliff offers a glimpse into an ancient, mystical world.

The remains of a majestic house that was once stood in the crosshairs of the Irish Republican Army.

This World War II relic let Allied pilots know they were entering neutral airspace.

You can see three Irish counties from this Neolithic hillside fort, once the seat of the Kingdom of Ailech.

This cemetery overlooking the Benbulben rock formation is the final resting place of one of Ireland's most beloved poets.

A stunning Victorian abbey and walled garden on a lakefront.

This stone harbor was key to Carnlough's limestone industry.

For decades, a bottle factory dumped their waste into these waters—now it's considered the best sea glass beach in England.

This short bridge is the only thing connecting a tiny Irish island to the mainland.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

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

Northern Ireland's Brobdingnagian stepping stones.

Once America's tallest structure, now a Baltimore landmark.

Baltimore's classic clock tower was once topped by a rotating, 20-ton medicine bottle.

A 200-year-old bar with a cheeky name claims to have served Edgar Allan Poe his final drink.

The ancient tomb acts as a calendar that keeps perfect time.

This center tells the story of one of the most famous battles in Irish history.

An ancient neolithic tomb that only sees the sun twice a year.

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

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

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

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

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

A museum marks and documents the site of the Titanic's launch.