CREATE TABLE table_30911 ("Round" FLOAT, "Date" TEXT, "Opponent" TEXT, "Home/Away" TEXT, "Score  ( Collingwoods score is in bold ) " TEXT, "Result  ( includes margin ) " TEXT, "Venue" TEXT, "Position on Ladder" TEXT)

Which venue did collingsworth play essendon in when they had the 3rd position on the ladder?
SELECT "Venue" FROM table_30911 WHERE "Opponent" = 'Essendon' AND "Position on Ladder" = '3rd'
SELECT "Venue" FROM "table_30911" WHERE "Opponent" = 'Essendon' AND "Position on Ladder" = '3rd'