Rancho Acalanes was a 3,329-acre (13.47 km2) Mexican land grant in present-day Contra Costa County, California.
It was given in 1834 by Governor José Figueroa to Candelario Valencia.[1] The name Acalanes seems to have come from Ahala-n, the name of a Costanoan native village in the area, or from the Saklan tribe, sometimes known as the Sacalanes [2] The rancho included present-day Lafayette and northern Orinda.[3]