Although Danny, the Champion of the World is a fictional story, it is based on Dahl's first-hand experience. Danny's home is a "real old gipsy wagon with big wheels and fine patterns painted all over it in yellow and red and blue."
The wagon described is almost identical to the one Dahl kept at the bottom of his own garden in Great Missenden, Buckinghamshire. Dahl bought the wagon for his children to play in, and spent a considerable amount of his own time in it.
The picture shows Dahl's wagon after it had been renovated, but it can be seen with its original colours in the Roald Dahl photo album.
Dahl also drew on his own experience for Danny's father's workplace. Dahl's first job was in a petrol filling station.
The picture shows what petrol pumps looked like in the 1950s.
The book is set in rural England, where Dahl felt most at home. "Hazell's Wood" is located six and half miles from where Danny lives. Although Hazell's wood does not actually exist, other places described in the book are in Great Missenden, Buckinghamshire.
Dahl moved here in the 1960s, and clearly loved the area. When Danny's father describes his own father inventing ways to poach pheasants he says, "...off we go over the fields and up into the big forest the other side of Little Hampden..." Dahl also tells us that three miles away from Danny's caravan is Cobbler's Hill. When Danny is walking with his father they go "along the road that ran between the hills towards Wendover." As can be seen from the map, all these places do exist. Cobbler's Hill is marked with the red marker.
Although we cannot be certain which particular wood Dahl based Hazell's Wood on, there are several woods in Great Missenden that match the description.
This video is a visual tour of the scenery in Great Missenden: