These "bridges" help confused bats cross the road.

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

Northern Ireland's Brobdingnagian stepping stones.

A hidden plaque is the only reminder of the lost palace where two storied English kings were born.

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

Soldiers carved these regimental badges into the chalk hills in remembrance of those who died in World War I.

The only pub in the world surrounded by an ancient stone circle.

A gated cross stands on the site where an Irish revolutionary met his end.

The whiskey producer's archives includes a historical list of infractions committed by and associated penalties exacted upon employees.

The house where the writer spent his formative years.

A massive Celtic cross secretly growing in an Irish forest.

The world's only flying boat museum honors a small Irish village that sent 20th-century aviation to new heights.

The modern birthplace of Irish freedom.

Once the longest bridge in Ireland, this rusting span sits abandoned and overrun by nature.

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

The "beautiful" equation predicting the movement of all electromagnetic particles is engraved in front of Newton's tomb.

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

Installed at a chaotic intersection, this gave London traffic cops a place to hang their heavy woolen coats.

The world's largest prehistoric copper mine had 30,000 animal bones scattered throughout the maze of passageways.

The last inhabitants of one of the U.K.'s most remote islands were evacuated in 1930.

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

A secret meeting in this small cottage changed the course of British history.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

The spot where three Protestant clergymen were burned at the stake during the reign of "Bloody Mary."