SELECT "county" FROM table_204_799 WHERE "name" = 'fairground street bridge'
fairground street bridge and confederate avenue brick arch bridge were both built in which county ?
CREATE TABLE table_204_799 (
    id number,
    "name" text,
    "built" text,
    "listed" text,
    "location" text,
    "county" text,
    "type" text
)