Why locals love it
Locals love it for three reasons: 1. It's a beautiful, well-restored home (owned and run by a non-profit); 2. It caters to locals as well with live theatre and events in Fall/Winter; 3. It's easy and fun to volunteer there (seniors, history buffs and ESL students love it), and volunteers are treated very well by the professional staff.
Mornings tend to be less busy-consider going then. Don't be shy to ask staff and volunteers questions about the castle or the family who built it.