JoAnn as far as i know there are no ruins in Jamacia. Lots of things you can do in Jamacia in a day. Have you done Dunns River Falls? also the river raft tour is a nice relaxing day, you are on long bamboo rafts and your guide gently polls the raft down the river, very scenic. Jamaica is one island where i would recommed booking a shore excursion through the cruise ship or hiring a bonded-cruise recommended driver for the day.