Literally ‘between rivers’, this term refers to the areas between river valleys or major water courses. These are higher than the valley floors and can be either ridges or more extensive plateaux. The wider interfluves may have significant water problems, either a lack of it, as on the sandy soils of the Breckland or the Sandlings, or too much, as in some parts of the clayland plateaux where the gradient is slight or where there are actually concave depressions, resulting in poor drainage.