This "railway" for boats continues a waterway over a road.

The house where John Wilkes Booth conspired with his co-conspirators.

A unique, eye-catching statue that carries an important message of hope.

A tiny island home to a former English slave fort.

This cave located in the badlands of Somaliland contains some of the oldest cave art in Africa.

Rusting railcars and locomotive equipment fill this Ethiopian train graveyard.

A powerful tribute to the victims who suffered under Ethiopia's most devastating regime.

Ethiopia's "smoking mountain" is in one of the hottest regions on the planet and is home to two lava lakes.

The hottest place on the planet.

The second smallest castle keep in England.

This historic former textile mill now houses a brewery, hotel, and what's believed to be the longest bar in the United Kingdom.

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

High in the clouds of San Marino sits an ancient tower with some curious prisoner graffiti.

Some say this medieval church is where the poet Dante married his wife and also met the love of his life.

The remains of an ancient Roman city are hidden underneath Bologna's beautiful public library.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

One of Ireland's most infamous prisons for rebels including men, women and children.

These airport hangars are now a bustling shopping center with only hints of its past still lingering.

The palace for King Gustav III was never completed, but the foundation remains tucked away in this city park.

A concrete Picasso in the middle of a student housing complex on the outskirts of Stockholm.

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

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

This seaside Scottish holiday rental lets you live out your bookselling dreams.