Stopped by this place on a whim the other day and loved it. The Newcastle Publick House is located on the feeder road which routes traffic to Damariscotta/Newcastle from Rt. 1: an old brick building on the left just as the road bears right for Damariscotta.
Excellent food: a wide-ranging menu with many local ingredients. Very reasonable prices and servings. Best little wine list I think I've ever run into. Dining available inside or on an outside patio (although traffic is loud). We loved everything we had. A standout fish chowder, also great salads and a lobster BLT. A serious range of fresh homemade fruit pies for dessert.
Small niggles: the lobster BLT seemed to have only claw meat. I didn't tear it open to double-check: honestly, in a sandwich like this it didn't matter. And the peach pie was bulked up with what seemed like tapioca: bad idea, especially when peaches are at the peak of the season and as cheap as can be. Nice fresh homemade crust and great flavor, but "B" for stretching the filling like that.
Don't let the niggles put you off tho: this is a very nice find.