The Margaret River Chocolate Company is a shamelessly popular stop on the northern wine road, part shop, part cafe, and part viewing area for the chocolate-making operation. It is not subtle, but it is fun, and the free tasting bowls explain why almost every touring car seems to pull in.
Use it as a light break between cellar doors, especially if you are travelling with children or non-drinkers. The grounds are pleasant, the cafe is serviceable, and the shop is useful for edible gifts that travel better than a bottle of wine in a hot car.