The well in the Château de Larochette - Larochette

Additional informations
Inside the Castle, in the "Créhange House", a deep well is carved into the massive stone rocks. A legend tells of the Lady who panicked as the enemy stormed the castle. She sprang into the well along with her infant child. Impressed of so much heroic courage, the aggressors stopped and they rescued the innocent victims from the well. As they needed a guilty party for the disgrace, they found the steward of the castle, who through his treachery had made the storming possible. They threw him into the well. The steward was transformed into a dragon who watches over the gold which he took in payment for his betrayal, and which lies in the well.
Apparently on each good Friday he awakes and emerges from the well at midnight and leads off a hellish round in the castle's keep.