We hadn't booked initially, thinking that even though it was Easter Sunday, it might not be necessary so early in the year. However, the queues were already quite long. So we went off for lunch and booked using a mobile, then we were able to walk straight in, bypassing the queue and simply showing our e-tickets on my mobile. Couldn't have been simpler, and saved such a lot of time and hassle. And the castle and ramparts are well worth visiting.