If you come to Ambergris Caye, take a trip to the north end of the Island. My Mother Shelley loves beachcombing and we go to Basil Jones near the end of the island to Beach Comb. You can take a full day tour to Mexico Rocks that include a beach BBQ. While the food is being prepared take a walk and you will find many shells, pomice stones and beautiful driftwood.
In Town you won't find many shells along the beach.