This relative relief map has been produced from data provided by Rosemary Hoppitt. Shading relates to the difference between the highest point in each 1 km square and the lowest point. To put it simply, the darker the colour the more slopy the area. There is a strong correlation between the flatness of an area and the ease of cultivating it. There is also an interesting correlation between relative relief and the distribution of ancient woods which tend to survive on areas which are difficult to access for farming.