An interesting and highly interactive hour and a half tour. Our girls aged 11 and 7 loved it, and there was lots of opportunities to have a go at presenting and lots of photo opportunities - perhaps not great for introverts. Guides were knowledgeable, enthusiastic and friendly and kept our interest as it was quite a pacey tour. There were about 15 of us on ours. Its not very easy to see where you are supposed to meet, as the entrances aren't clearly marked - head for the daleks! Manned receptions in other buildings meant we were able to ask so it wasnt a problem. You can't take in back packs but there are lockers. As Blue Peter badge holders our daughters got in at reduced rates, so it was extremely good value. Definitely worth booking - but note we had to book about 3 months in advance!