'The Letters of Utrecht' lays out a ribbon of poetry one letter at a time, with no final verse in sight.

Visitors can still take a train to this former train station turned museum.

The world's largest bicycle shelter can hold more than 12,500 two-wheelers.

Underground attraction offering tours of the foundational ruins of a church nave that collapsed in 1674.

This still-celebrated home was a radical architectural experiment in 3D De Stijl.

The cutest way to stay safe in traffic.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Old Danish castle immortalized in Shakespeare's Hamlet.

The palace window through which Protestant nobles flung two Catholic regents, thus sparking the Thirty Years' War.

An eerie, existential museum dedicated to the author of "The Metamorphosis."

Climb inside an iron crystal magnified 165 billion times its normal size.

An ingenious way to immortalize the inventor of universal time.

One of the world's smallest functioning lighthouse boasts an unexpected connection.

The long-lost final resting place of an accused witch.

The raised stones in the middle of this road through Culross are relics of a 17th-century class divide.

The castle that provided the setting for much of 'Monty Python and the Holy Grail' is now a pilgrimage site for fans.

This man-made waterfall was designed to help improve access for spawning salmon.

The most northern place on the mainland of Great Britain.

This unique building in the main square stands out among the city's typically Baroque architecture.

Malta’s oldest sea water distillation building is now an architectural anomaly on the Sliema waterfront.

This subterranean necropolis holds three floors of antler-dug grave caves.

One of Malta’s most important Neolithic sites sits in a suburban area south of the country’s capital.

The eyes and ears of this tower keep watch over Malta’s Grand Harbor.

For over two centuries, this palace served as a residence for the Holy Roman Inquisition's leaders, a courthouse, and a prison.