Mystic Lake is a 149-acre natural kettlehole pond located in Marstons Mills, Massachusetts, part of the larger Indian Ponds complex that includes Middle Pond and Hamblin Pond. Formed by glacial activity, this scenic lake features crystal-clear waters with excellent 18-foot transparency and reaches a maximum depth of 42 feet with an average depth of 20 feet. The lake's sand bottom with scattered gravel and rubble areas, combined with sparse aquatic vegetation, creates ideal conditions for a diverse fish population. Fed by groundwater and cranberry bog drainage, Mystic Lake serves as the headwaters of the Marstons Mills River and maintains relatively light fishing pressure due to its challenging access, making it an excellent destination for anglers seeking quality fishing experiences.