Blackbeard's Castle or Paradise Point for young kids?

Hi, All!

Looking to take our first cruise as a family this summer, and we are trying to find affordable things to do in St. Thomas that do not involve a beach day. We love the beach, but have a dolphin encounter/beach time and another beach/snorkeling thing in mind for some of our other stops, so we're looking for something easy and fun (and cheap!) that we can do with our 5 & 8 year olds. Came across some info. on Blackbeard's Castle and it looks neat. A little history, food/drink options, pirates, cool photo ops...it sounds decent, but I can't find much recent info. on it. Has anyone ever done this on their own (not part of a tour)? I was thinking we could take a taxi to the area, walk up the 99 steps (I can already hear the kids complaining! lol), and then go up to the castle that way.

If anyone has ever done this and would have some info and/or pics to share I would be so grateful. Have also not ruled out going up to Paradise Point,but it seems the views from the top are similar to up by Blackbeard's. Just trying to get some ideas.

Thanks!