Monkeys lounge around at this 13th century temple.

Thailand's distressed elephants find peace at this Chiang Mai sanctuary.

Six times a day a train runs right through the middle of this Thai street market, sending vendors scrambling.

At the right time of day, sunlight floods through the roof of this cave and illuminates the small pavilion hidden within.

The first spinning jail built in the United States is the only one that still turns.

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.

A beautiful little museum hidden away in the heart of Barcelona holds a treasure trove of Ancient Egyptian artifacts

For one day every month Barcelona's Estació de França transforms into a market for model trains.

Occupied for six centuries by Franciscan Order nuns, this monastery is an amazing ode to Catalán Gothic architecture.

A once grand hotel now sits eerily abandoned in the Catalan countryside outside Barcelona.

A once-secret library of Freemason history in Catalonia.

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

One of Europe's largest supercomputers is housed inside of a disused chapel.

Turntable anonymously received orphans, alms, and groceries.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

A stately palace has been converted into the world's largest cannabis museum.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

This cemetery features modernist statues as strange as its name.

A beautiful but toxic fountain of mercury.

This semi-secret storybook hedge maze is also the oldest garden in the city.

An iconic and controversial ancient Iberian funerary urn with a hauntingly penetrating gaze.