CREATE TABLE table_6224 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Result" TEXT, "Game site" TEXT, "Attendance" FLOAT)

Game site of candlestick park had what opponent?
SELECT "Opponent" FROM table_6224 WHERE "Game site" = 'candlestick park'
SELECT "Opponent" FROM "table_6224" WHERE "Game site" = 'candlestick park'