The Ardenwood Forge Blacksmith is open on certain days at Ardenwood Farm. While it is free with admission to Ardenwood, it is usually only open on high admission 'event' days at Ardenwood.
Essentially this is a working blacksmith forge representative of ones that operated 100-150 years ago. It still makes viable tools and you can even buy items (from kitchen implements to a horseshoe with your name on it) made there. Kids usually enjoy seeing the big fire and watching the blacksmith at work and there is a nice high counter to prevent them from running in there.
This is definitely worth a stop if you are already inside the Farm.