Green Lakes State Park is a New York State Park located east of Syracuse in the Town of Manlius. The park is strikingly scenic, and has a "masterpiece" golf course designed by Robert Trent Jones very early in his career. Green Lake itself is perhaps the most studied meromictic lake—one in which layers of water do not mix—in the world. The park preserves the largest stand of old growth forest in Central New York, and Round Lake has been designated as a National Natural Landmark by the U.S. Department of the Interior.