The Cobe Estate, also known as Cariad or Oak Hall, is a historic summer mansion house on Bluff Road in Northport, Maine. Overlooking Penobscot Bay, this 1910s mansion is one of the largest Colonial Revival houses in the state. It was built in 1912-14 for Chicago lawyer Ira M. Cobe, and was listed on the National Register of Historic Places in 1983.