Antique Real Photo Postcard. Identified as a boat on Annabessacook Lake in Winthrop, Maine. Published by Eastern Illustrating and Publishing Co. Divided back, postmarked 1957 from Winthrop. Condition: This is an original photo postcard, not a copy or reproduction. It has traces of a postal cancel on front. Comments: Annabessacook Lake is a lake located in the towns of Monmouth and Winthrop, Maine. It is 49 feet deep, and covers about 2.2 square miles in surface area. It is one of the major bodies of water in the Winthrop Lakes Region.