During the Trail, each venue will have one or more items of treasure displayed in full sight for you to discover - crowns, diamonds, jewelled rings and even slithering snakes and trundling turtles.
As you wander the Trail, keep an eye out at each venue, and then mark off your finds on the back of this year’s Trail postcard (here's the large JPEG version). You can pick these up from venues, including the Southville Centre.
Keep your postcard safe from pesky pirates - when you have marked off 5 or more items of treasure, if you show it to the kind people at the Southville Centre you may well get a golden chocolate coin from the pirate horde (as long as the horde lasts!) in return for your diligent hunting!