A cadastral map is a map showing the boundaries of subdivisions of land. It is based on bearings, lengths and areas of individual tracts, for purposes of describing and recording ownership. Some areas on the cadastral map may also show topography, drainage, and other features relating to the value of the land and its uses. The cadastral map number is the first number used in the series of three numbers for determining the County Grid Number. The Cadastral Map layer is comprised of the County Cadastral Maps series that cover the entire County of Santa Clara. It contains 281 individual maps and numbered from west to east and from north to south. Cadastral Map No. 1 is in the northwest area of Santa Clara County. Each cadastral map covers approximately 150,000,000 square feet. The information on these maps were last updated about 1986-1988. A corner record is the means by which the re-establishment or rehabilitation of public land survey corners or other property corners may be made of record and brought to public attention.