The enchanting archway is the only surviving portal into Dublin's lost medieval wall.

These disused steel furnaces are now haunting ruins that may one day be a national park.

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

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

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

This public park was the site of the largest civilian disaster of the Civil War.

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

An 18th-century Catholic church converted into an eccentric temple of music and bacchanalia.

Color-coded signs direct drivers on a network of routes designed to avoid Pittsburgh traffic.

A giant ball made from pieces of an old Jeep.

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

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 serene public space nestled within the remains of Glasgow’s Victorian maternity hospital

With 3,000 bikes on display, the world's largest bicycle museum includes some famous rarities.

The ruined remains of the airport Claus von Stauffenberg departed in his failed attempt to kill Adolf Hitler.

This French Canadian classic is a specialty of the oldest continually used church in Minneapolis.

Once the most painted on object in the world, this short campus fence is well on its way to being so again.

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

A take-out restaurant that only serves cuisine from countries with which the United States is in conflict.

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

The largest clock face in the United States is twice the size of Big Ben and infinitely more ad-sponsored.

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

Meet your friends, marry your true love, or tell your enemies to kiss your butt under this historic Pittsburgh timepiece.

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