15" x 20" architectural Vellum with a lithographic map of a city block, enumerated with its Tax Block number, divided into lots with lot line and measurement, a cadastral map from the planning and zoning department of San Francisco. Produced in 1950 and updated through 1958 for regular use. Fine original condition with visible stains or not as shown . Pencil marks are removable, stains not so much so look closely.