Rancho Aptos was a 6,686-acre (27.06 km2) Mexican land grant in present day Santa Cruz County, California given in 1833 by Governor José Figueroa to Rafael Castro. The grant on the Monterey Bay was immediately downcoast of his sister, Martina Castro's Rancho Soquel, and upcoast of his father, José Joaquín Castro's Rancho San Andrés. Rancho Aptos stretched from the area just to the west of Aptos Creek to parts of Nisene Marks and Day Valley in the north, and Rio del Mar to the east, including present day Aptos.