Nightmare at Gravity Hill Posted by Scaredy Pants | Sep 12, 2016 | New Jersey Haunted Houses | 0 | Nightmare at Gravity Hill New Jersey From $20 Address: 1005 Farmingdale Rd, Jackson, NJ 08527 (732) 703-4198 Welcome to Nightmare at Gravity Hill. Do you like Scary? This is no Hayride! It’s a 35 minute Walk of Terror! Don’t miss Nightmare at Gravity Hill New Jersey.