Relief and drainage
Berkshire’s relief is shown with the lowest areas in green, shading to pale brown with increasing altitude. The density of the dark brown contour lines indicates the steepness of the terrain.
The highest parts of the Downs in the north west reach 225m and in the south west, Walbury Hill is 297m. The Pang, Kennett and Loddon drain into the the River Thames, with its lowest point in Berkshire at 21m.
The west of Berkshire consists predominantly of chalk downland; the lower land in central and east Berkshire is on London clay with superficial sand and gravel on the river valley bottoms; along the southern border and in the south east are the Bagshot beds giving a sandy acid soil. The Berkshire Geology Group provides more information on the geology of the county.