Own this Attraction? Mayhem Haunted House Mayhem Haunted House is a Haunted Attraction located in Ottumwa, IA. Location 13011 120th AveOttumwa, IA 52501 (Click for Fullscreen Map) About This Attraction: Haunt Types: Links: Contact: Mayhem Haunted House Guest ReviewsGuest Average: 10 out of 10 Tera – 10/10Supoer scary haunted house that is FILLED with great actors and super detail. Awesome place to go …show more if you want a great scare and lots of fun at a really good price. View All Submit Your Own Review! See anything that needs updated? Let Us Know!