Terrifically morbid cemetary and site of famous Paracelsus' grave.

These paved rills bring freshwater into Altstadt and could spell wedding bells for whoever stumbles into the waters.

The most impressive of Basel's three remaining city gates.

This artistic fountain display pays homage to this area's theatrical history.

This ferry carries passengers across the Rhine propelled by no engine or paddles but by the river's current.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

It leads to a former hospital’s old root cellar.

A subterranean world of tunnels links several buildings of this rare 19th-century asylum.

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.

One man's attempt to create an artistic wonder on a run-down block in Detroit.

This resort community was known as the "Black Eden of Michigan."

A small cemetery chapel designed by Frank Lloyd Wright and built in 1906.

Arguably the best example of an authentic Dutch windmill in the United States, rivaling its counterparts in the Netherlands.

This softly rounded mansion was built without corners not to avoid evil spirits, but to make them more comfortable.

These mansions date back to Chicago's days as a brewer's paradise.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The ruins of a medieval monastery named after a type of tree.

A restaurant with an extensive Irish whiskey bar also has several first editions of famous works by Irish authors.

This modest plaza in Moneygall, Ireland has cashed in on its distant connection to the U.S. president.

The secret skeleton of a murdered nun was discovered in this church basement, but the scandal doesn't end there.

This lighthouse and shipwreck museum keep a torch burning for the memory of the SS Edmund Fitzgerald.

A painted-over wall in Detroit originally built to segregate a black community from an adjacent white development.

To truly appreciate Detroit's landmark skyscraper, you have to step inside.

The only surviving prototype for Buckminster Fuller's house of the future.