From the Richmond Whig, 5/1/1865

THE KEY OF CASTLE THUNDER. - Some person in the North, who was at one time a prisoner here claims to have carried back with him as a trophy, the identical key that slipped the ponderous bolt in the massive front doors of Castle Thunder. The importance of that key must have been exaggerated. Castle Thunder is still used as a prison, and we presume the key is still a useful and necessary part of its outfit. If any key has been carried North, it must be a key of minor importance, a ward or cell key, or something of that sort.