Grafton Notch State Park was a pleasant surprise. I’ve known of it for a while. (Driving through at dusk is apparently the closest you can ever get to guaranteed moose sightings.) We headed up here to see a nearby waterfall, and then realized we’d hit the park. That waterfall was forgotten.
The Moose Cave walk is a treat. It’s a quarter mile, and while you can’t get a stroller down there, anyone ambulatory can hack this walk. There’s a neat gorge, some amazing moss gardens, and a patch of reindeer moss. Totally worth a stop as you drive through.