If you find yourself in London, then I'd highly recommend the Sea Life Centre London Aquarium as an interesting place for people of all ages. The place is so well presented, really atmospheric lighting with mood music and different environments recreated. The assorted fish and sea creatures are fantastic. It takes about an hour and a half to two hours to go round. As you can hear from the clips it can be a bit noisy but that's all part of the atmosphere. Here's some photos and footage from my own visit there on Friday. Exhibits and penguin behaviour can vary!