It's an interesting town to explore a little, has historic buildings and picturesque waterfront, the floating market, floating bridge, a few casinos if you're into that. You can walk to most everything downtown you'd care to see. My favorite part is just watching the variety of boats and ships going by. I've seen signs for a boat tour of the inner harbor which I think would be interesting, but it only ran one day a week and we've never gotten around to it. There is a fair amount of shopping and restaurants, some scattered around downtown and some concentrated on the oceanfront in Riffort and Waterfort Arches.
The channel to the inner harbor goes right through the middle of town and there's no way to drive across right there, so you'll usually just park on the side you're coming from and walk across the floating bridge (or take the free ferry) to get to the other side. There are parking lots on both sides, and we've never had problems finding a spot on the Otrabanda side, at least in the late afternoon or evening. It's worth driving over the big bridge at least once for the view though, even if you have no other reason to cross.
I haven't done the caves or the park, but I've heard the Ostrich farm is interesting. The aquarium is small but nice.
