One of Jeff Koons’s largest sculptures and his first commemorative work.

One of the oldest wine cellars in Germany is now a restaurant beneath Bremen's town hall.

This medieval tower is all that remains of the castle where Joan of Arc was held before being burned at the stake.

Conspiracy theories and occult legends surround this mysterious natural rock formation.

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

On rare days, this abandoned castle's gatekeepers open its doors, revealing the eye-popping splendor hidden inside.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

Science fiction's grandfather has a fittingly marvelous tomb.

A 14th-century fortified keep showcases the masterpieces of an ingenious 20th-century clockmaker.

Notorious artist squat renovated into legal studios.