Sept can be a little cold on the cape, although sunny weather is more like than other months. You won't see many landmark, but you will have a load of opportunities to shoot marshes, sand dunes, lighthouses, and shore line. Your range will be from bottom Hyannis to the tip P-Town, which is a 2 or less drive. But your best bet would probably in the Cape Cod National Seashore area. Hope you enjoy it ...