Date: October 4-November 2 (weekends only)
Cost: $54.99 adults, $34.99 kids under four feet, free for kids two and under (online ticket special: $29.99 for admission October 4-5, 10-13 or November 1-2, $34.99 for anytime admission)
What to expect: There's trick-or-treating during the day, but at night, Six Flags Great America turns into a land of ghosts and ghouls, with kids' activities (including a Halloween-themed Wiggles show!), two haunted houses, a parade of ghouls, a human freak show and much, much more. Check the website for the full schedule of activities.
Additional info: Note: no costumes are allowed at night.