Pre-booked the tickets before we travelled but I am not sure whether this saves you any time to be honest, we still had a short queue outside before entering. The place itself has plenty to offer however, the tours themselves (know as tram tours) only seem to be bookable on the day. I recommend downloading the app before travel and seeing if you can book onto some of the tours before you get there. The app doesn’t allow you to book onto two tours, even if they may be 2 hours apart. Tip- other members of your party also download the app and one of you books one tour, the other books a different one. The time slots are released throughout the day and seem to be really popular. The personal highlight was the white tour which covered the control centre, you don’t spend long there but it is definitely worth the visit. The food and drink was a bit expensive, as was the gift shop. As a coeliac I didn’t see any gluten free options that looked like they were clear of cross contamination but I also didn’t ask. There were crisps to eat but no gf sandwiches I could see.