Where a railroad loops under or over itself to rise or drop more than 70 feet in a short distance.

Three plaques mark the spot where the "forgotten father of broadcasting" worked.

A sparse, solitary sequoia still stands as a living tribute to the famous conservationist who planted it—but it's dying.

This nearly 200-year-old restaurant's history includes an exiled French prince, JFK, and a very hungry Daniel Webster.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

The oldest attraction in Disneyland is a prehistoric stump that Walt may have bought for his wife.

Centuries of crashing waves carved out this small hole in the rock, which lights up at certain parts of the year.

The world's most active stratovolcano is almost always erupting.

Ancient snack bar of the Roman Empire re-opened.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

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

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

The library's graceful rotunda is like a bibliophile's temple.

A king's bloodstained shirt is among the gruesome collection of artifacts displayed below Stockholm's Royal Palace.

It houses the remains of a 17th-century version of the Titanic.

These spartan apartments are provided to clergymen visiting Vatican City.

Breathtaking and huge 430 year old maps of Italy.

A Serbian church lit by chandeliers made of weapons.

This picturesque medieval monastery guards a small trove of historic treasures.

The complex has been abandoned since the Croatian War of Independence, barring a stint as a set for 'Game of Thrones.'