Not been to the New Den, went to the old ground several times. Very intimidating atmosphere, wasn't a place for a young child then, you wouldn't have been able to relax. Having said that it was a good few years ago and may well have changed since then.
Youll be fine inside the ground if you stick to the width of the penalty area behind the goal. We only have the upper tier so their fans cant get to you. Its outside the ground when the fun begins and when I was there, it was our own fans that started it.