The Friends of Billerica Recreation has discounted Canobie Lake "Screeemfest" tickets available for purchase $29 each at the Billerica Recreation Department Office. Screemfest includes haunted houses, special walk around characters, outdoor haunts, rides and "Rocktober Fest" performances. Park is open Fridays, Saturdays, Sundays from 9/26 - 10/31.