Many great things to do.
As well as what is listed in the above posts there is a great pirate museum locate in a large purplr building locared 2 blocks behind the straw market. Takes about an hour to do and cost $12 per person.
Also a horse and carriage ride right at the port that takes about 20 to 25 minutes to do. it is narrated, but the traffic noise makes it hard to hear. but it is fun and just something you dont do everyday. it was $10 per person, tip if you like. we really enjoyed it.
2 hour historical city tour was very good. Our guide was very noligible and very friendly. we saw Queen Anne;s staircase, fort Fincastle, another fort and more. One of the forst had a guided tour and was really interesting to do. There were small table set up to buy souvenirs at 3 places we stopped at too.
The Dig at Atlantis is very good. I dont usually like aquariums, but this one is worth seeing. really great. The tour does go fast, but afterwards you can go back through on your own at your own pace to enjoy it better. just keep on your wrist bracelet as proof you paid for it.
You can take a taxi and pay admission if you dont want to do the excursion.
Skip the Sunshine Glass Bottom boat excursion, we only saw maybe 6 fish and one sand dollar, the boat was old and dirty. plus the stairs to go dwon were steep and difficult to navigate. At the bottom there is a wall around the glass bottom so if you have young kids you will have to hold them up so they can see.
Next month we are going to the Gardens so I cant comment on that yet.
Plenty of great stuff to see!!