An urban laboratory.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

England's oldest surviving hedge maze has been confusing visitors for over 300 years.

This concert pavilion on the shore of the Great Salt Lake has been destroyed by fire, water, and disinterest but keeps coming back.

You thought Santa Claus didn't exist, but it turns out you were wrong.

A gothic church spire sits atop this skyscraper, the tallest church in the world.

The National Railway Museum in York is the largest railway museum in the world, attracting almost 1 million visitors per year.

The last bastion of Roman presence north of the Alps looms over a German town.

Two stunning 17th-century libraries and a cabinet of curiosities.

The king of U.S. high points towers over every other peak on the continent.

A fantastic castle rumored to be the birthplace of King Arthur.

Dublin's "Dead Zoo" serves as a window to Victorian museum design.

This stately monument has been wearing a traffic cone hat for decades much to the delight of the locals.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

A world-class observatory in the California desert.

A small park on Bourbon Street features life-size bronze statues of New Orleans musicians.

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

The "Prussian Versailles" that is as glorious today as when it was built.

Bridge that died in war and was resurected.

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.

Monasteries on rock pillars, once accessible only by frayed ropes.

A burnt orange monolithic dome structure perched on a hillside near Interstate 280.