When I was a kid and Dad was working (he was a train driver so we got cheap travel) if Brighton was too far away for me to go on my own I always would go to Portsmouth or West Ham. Amazing really thinking about it now. Imagine 10, 11 year olds going to London or elsewhere on their own nowadays.
I would not let one of my sons(nearly 10) down Newhaven town centre on his own.
What years were you going to Portsmouth/West Ham?