Here is a sample imitation of the walls of Troy with local granite on Cape Cod. This imitation requires a retaining wall of at least 5 feet with a concave curve. The walls of Troy, pictured below, used notches to facilitate the curve, avoiding the use of corners which could be undermined with battering rams. This sample was assembled in a Wellfleet driveway. See our blog post on Troy for more on the city and walls built nearly 4,000 years ago.