In addition to Walls, each player starts with 4 Sea Towers that will (hopefully) stop early naval rushes. Given how cramp starting areas are, all huntables and extra herdables are located outside players' walls. Empire Wars is partially implemented on this map; you'll start with a Lumber Camp and a Mill, but you'll be missing all the other buildings and you'll only start with 11 Villagers.
This map comes in 7 themes: Asian, Autumn, Desert, Grassy, Mediterranean, Tropical and Winter. The create_land commands used to create the ring forest were taken from TheMadCADer's Arena-ception RMS.
You can also download this RMS here: