user: Question: Tell me the county for Mariano Castro
Columns: ['Concession', 'Date', 'Grantee', 'Size', 'County']
Types: ['text', 'real', 'text', 'text', 'text']
Sample row: ['San Pedro', 1784.0, 'Juan Jose Dominguez', 'acres (km2)', 'Los Angeles']
SQL:

assistant: SELECT "County" FROM "Table" WHERE "Grantee" = 'Mariano Castro';