SELECT "location" FROM table_204_929 GROUP BY "location" ORDER BY SUM("maps") DESC LIMIT 1
what location has the most maps ?
CREATE TABLE table_204_929 (
    id number,
    "location" text,
    "name of mill and\ngrid reference" text,
    "type" text,
    "maps" text,
    "first mention\nor built" text,
    "last mention\nor demise" number
)