An 1814 castle that hosts an exhibit of "explorabilia".

While only two of the ancient buildings at this site are actually churches this was one of the earliest Irish pilgrimage sites ever.

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

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

Perfectly preserved ancient monastery in an impossibly dramatic location on a rocky island in the Atlantic.

This plaque marks a place where one of Hollywood’s most famous dancers got his start.

The souvenir got the company’s founder out of a pretty pickle at the World’s Fair.

This historic Pittsburgh tennis complex is a rare example of natural red clay courts.

This spot memorializes one of the greatest plays in NFL history, unless you happen to be a Raiders fan.

The legacy of baseball great Roberto Clemente is preserved in a retired Pittsburgh fire station.

Sections of the iconic limestone columns have been left uncleaned as a reminder of the city's polluted past.

A portion of the old Pirates stadium over which a defining home run once flew still stands even after the rest of the stadium was torn down.

Once used to screen films for theater owners to rent, this historic building is now a start up hub.

A model of a dinosaur that was named for Andrew Carnegie stands outside the museum that also bears his name.

The residents of the Neighborhood of Make-Believe live without much fanfare within the Pittsburgh Children's Museum.

This eccentric mansion museum holds a impressive collection of rare and automatic instruments.

A quiet, gothic haven nestled between Pittsburgh's Squirrel Hill and Point Breeze neighborhoods.

There aren't too many operational funiculars around, but Pittsburgh has two!

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

The only way to see Pittsburgh is from the top of this lookout point, just like the ancient members of the native peoples did.

A restored Pittsburgh house of God has been converted to a marvelous house of suds.

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

Why have you never heard of the second most popular tourist site in New York?