 A sheet of mainly Jurassic limestone fan gravel probably covered most of the vale in the past but has since been eroded away leaving isolated deposits, most notably the Cheltenham Sand, which forms a well-draining light soil in the Cheltenham-Gloucester region.The Middle-Jurassic oolitic limestone series which forms the bulk of the Cotswolds hills contains the best-known of the county's rocks on account of its extensive use throughout the area as a building stone.All from churches to humble cottages have been imbued with a mellow, warm character from the golden yellow colour of the stone - to which many ‘honey-pot’ Cotswold towns owe their modern popularity and prosperity.