These shore excursions will give you an idea. Even if you aren't sailing with the cruise line whose information we have here, they will still be a good reference for you.
Most cruise lines offer similar shore excursions in the same ports.
Even if you plan to do sightseeing on your own, these will still give you some ideas about what there is to see in each port. Another excellent source of information about ports of call is Weissmann Travel Reports. We offer these at a discount for Cruise News Daily readers. Please check the current list of ports available.