A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

This lovely hilltop tower was specifically built to withstand 100 MPH winds.

An overgrown garden stands as a grim marker of an unrealized dream.

A small Richmond island dotted with the remnants of hundreds of years of history.

Heron, whitewater rapids, and urban industrialism all add to the beauty of this concrete nature walk.

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

Among the oldest structures in Madrid, these Moorish walls once guarded the medieval city of Mayrit.

This sprawling farm was once a Cold War-era hideaway for the nation's top diplomats.

In the fictional world of Kcymaerxthaere, celestial wonders marked a portal to a powerful route of travel at this site in Madrid, Spain.

An ancient Egyptian temple in the middle of Madrid, Spain.

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

A temple to modernity, tucked away amid Barcelona's more well known museums.

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

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

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

A beautiful but toxic fountain of mercury.

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

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

A moody and picturesque riverside ruin overgrown with vegetation.

After being destroyed by IRA sympathizers, the ruins of this stately Irish manor have sat vacant for decades.

An unusual manor of stunning beauty, born out of a crippling disease.

This floating garden in the sky is straight out of a fairy tale, but the real thing is nothing short of magical.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.