A remarkably intact castle that once was the largest in Ireland.

A hugely vast Irish landscape of barren rock that stretches for miles.

This singular Irish dolmen is more Frank Lloyd Wright than upright stonehenge.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

The famous sculptor left his mark on this Italian wall in an internationally protected example of street art.

Drink wine handed out through a window as part of an age-old tradition.

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

Southern Italy's spinning top village.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

An unusual round church in London with a Templar past.

Dictionary Johnson’s favorite feline.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

A submerged archeological park still holds the wonders of a Roman Sodom.

This 15th-century structure had a long, tortuous journey to its current location.

A sculpture in a secluded garden honors one of Edinburgh's most innovative thinkers and city planners.

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

The colorful stairs are made with marble from the world's major quarries.

Once a lonely sentinel on the edge of the Great Plains, this rebuilt trading fort offers a glimpse of life on the Santa Fe Trail.

A mental health hospital dating back more than 139 years, now features a museum.

This memorial pays homage to Pueblo's four Medal of Honor recipients.

This three-mile concrete levee in Pueblo, Colorado was transformed into the world’s longest painting.