The verdant mossy ruins of a Franciscan monastery lie in the remote Sintra hills awaiting exploration.

A unique seaside cave where Aleister Crowley faked his own death.

One Portuguese poet described this cape, the westernmost point in mainland Europe, as "where the land ends and the sea begins."

In Portugal, a secluded stretch of untouched natural beauty hides at the bottom of a steep hill.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

Cold war icon and onetime "hole" in the iron curtain.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

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

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The star-studded street honors the city's most notable Brummies.

The oldest inn in England served brew to the crusaders.

One of Europe's oldest libraries.

A theatre built to house the rowdy Oxford graduation ceremonies became the stage for a debate about God's existence.

The beams of the New College, Oxford dining hall come with an amazing story.

Hidden in plain sight, this creepy sculpture watches from above.

The spot where three Protestant clergymen were burned at the stake during the reign of "Bloody Mary."

The stoic structure boasts a whimsical set of stained glass art commemorating Lewis Carroll.

The beautiful non-repeating pattern honors the Oxford professor who discovered it.

The remnants of this unusual bridge await an uncertain fate.

Puzzles within puzzles hide a golden treasure in this hedge maze.

A miniature village mimics the surrounding buildings so well it includes itself.

Singapore's Ang Mo Kio Town Garden West is a social hotspot for songbirds and their humans.