World's first "penitentiary," meant to be humane, drove men insane.

A lush green oasis in the middle of Chicago.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

A Victorian marvel of engineering is now a 21st-century tourist attraction.

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

A meandering boardwalk across the bogland leads to a "stairway to heaven" with sublime views.

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

Northern Ireland's Brobdingnagian stepping stones.

Follow lines from a W.B. Yeats poem through interconnecting gardens designed to appeal to each of your senses.

This natural sea arch highlights Ireland's rugged coastal beauty.

A stunning Victorian abbey and walled garden on a lakefront.

A spectacular hidden beach in Ireland has the dark, disturbing nickname of "Murder Hole Beach."

Local legend says the remains of Father Christmas lie within the medieval grounds.

This 900-foot structure with 20 arches crossing a Scottish river was built in the late 19th century.

On a hill overlooking Loch Trool, a granite boulder marks the site where Robert the Bruce, King of Scotland, defeated an English army.

This impressive midden of scallop shells apparently all comes from a single fishing company.

The location of the Bridge of Death and the Gorge of Eternal Peril in "Monty Python and the Holy Grail."

This unusual rock looks like a giant, otherworldly mushroom sprouting atop a cave.

This waterfall is one of the most spectacular natural features in the Scottish Lowlands.

Described by William Wordsworth as a "World of Wonder."

The abandoned transportation hub hides within the Glasgow attraction it once served.

A sea cave with a waterfall and Viking past

These ruins are a hidden gem, complete with fantastic views over the cliff edge.

A fernery hidden by neglect is uncovered, and an ancient specimen along with it.