"Barncastle", also known as Kline Cottage, is a historic house, now an inn and restaurant, at 125 South Street in Blue Hill, Maine, United States. It is one of the earliest and largest summer cottages in Blue Hill, and remains one of its most visible and idiosyncratic. Listed on the National Register of Historic Places and originally called "Ideal Lodge" after the Boston Ideal Opera Company founded by its builder, Effie Hinckley Ober, the house was finished in 1884 to a design by George Asa Clough, Blue Hill native and noted Boston architect, Effie's childhood friend.