Sea Life London Aquarium

The walk-through route swings from bright galleries into deliberately dark ones, with tactile displays set into the Rainforest and Rockpool Explorer sections — crocodile skin and piranha models children are meant to put their hands on. That swing in lighting, together with music and screens, is the one thing to weigh up if your child is sensitive to it: the aquarium runs a quiet session on the first Sunday of each month, by pre-booked ticket only, with the music off and the lighting held steady. For an ordinary visit, weekday afternoons in term time are the calmest stretch of the week.