Legend says this cave housed a 16th-century cannibal and his family of 48.

The solitary cairn marks a mysterious death that's still controversial more than two decades later.

A private home envelops the ruins of this 13th-century priory.

Overlooking a Scottish loch, this beautifully crumbling castle once inspired a poem by William Wordsworth.

This eclectic sanctuary is a hodgepodge of various architectural styles, all crammed into one building.

The ruins of a defunct limestone quarry still haunt this Scottish promontory.

The Titanic sails again in one Scotland man's backyard.

Nicolas Schöffer's massive interactive sculpture was assembled in 1961 and brought back online in 2016.

This abandoned Belgian fortress is purposefully being left to nature.

A former customs station on the border of Germany and the Netherlands.

A distinctive former power plant turned university lecture hall looks like it could make you breakfast.

This bakery and museum offers tours of the tastes and mythology of Aachen's signature spice biscuit—just don't ask for the recipe.

The largest bell in the world has been swinging high above a Cologne cathedral for almost a century.

A poignant mural honors the heroic teenage non-conformists who took on the Nazis and paid the ultimate price.

The largest mosque in Germany.

The final resting place for a wealthy Roman family, this tomb might be the best preserved of its kind outside Italy.

Residing along a busy thoroughfare, this sculpture urges passersby to consider the future.

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

A church filled with the bones of hundreds of virgins martyrs—or so they say.

An elegant chandelier hangs over this ancient sewer chamber, now open for concerts and public tours.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

This small condiment museum makes all manner of mustards with a 200-year-old mill.

If the tunes of antique organs and musical marionettes don't intoxicate you, the draft beer certainly will.

Nestled in the heart of Milan is a real wunderkammer of morbid curiosities.