Tour the Mount Gay Rum Factory
It is possible for the younger backpacker to walk to the factory through some interesting surburbia to get to the Rum Factory - I call it the factory as the rum is distilled mostly at another plant - however you see all the equipment that gets the process from Sugar Cane Molases to the bottle.
It is a fun thing to do isn't too long and is a great way to meet fellow visitors to Barbados. The guides do a great job in telling you the story of not only how rum is produced but its the story of how rum really came to be as this island is where that happened. So yes you learn how rum was invented on the island of Barbados.