The history and future of cannabis.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

The works of poetry's biggest names grace the walls of the city of Leiden, all carefully painted by hand.

Lumps of significant stone from around the world surround a flaming monument for peace.

A book bound in the skin of an infamous criminal, along with countless other specimens.

Remnants of the 16th-century defensive wall still stand unassumingly within Edinburgh.

Displaced highlanders would take shelter from the wet Scottish climate under the large walled bridge at Glasgow Central Station.

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

A scattered trail of street art adds a pop of color to the city's stark structures.

Southern Italy's spinning top village.

"Respectful to the dead, safe and sanitary to the living, dedicated to the Genius of Memory..."

A 200-year-old collection of oddities and medical paraphernalia.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

An eccentric collection of antique items shares space with a prop-quality witchcraft museum.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

A 16th-century Andalusian palace.

The world's largest wooden structure.

The body of at least one victim of a construction accident was left behind in the collapsed pylon, buried under tons of concrete.

A whimsical bridge uses saxophones to pay tribute to two great men and the European Union.