We went to Ha Long for the boat trip, and wondered "what else is there to do here with the kids"? We drove past Sun World, and decided to check it out. Whether the amusement park or the cable car ride, the inexpensive tickets are all-in... you can visit everything; take in all the rides; and there was never much of a line for anything. The Water Puppet Show at the top of the hill is in Vietnamese, but you don't need to understand Vietnamese to follow the plot and be entertained. Brilliant performance.