About Our Facility Our Castleton storage facility, located at 8525 Castleton Square Drive, can be easily reached by common roadways like 82nd Street, Allisonville Road, and Highway 421, and is within walking distance of attractions and shopping establishments like the Castleton Square Mall, Castleton Square Pavilion, Costco and much more. At Simply Self Storage Castleton, we put your security first. That’s why we monitor the premises of our fully-fenced facility 24/7 with security cameras and usee keypad entry to keep your belongings safe. It’s also why we’ve lined the interior and exterior of our facility with bright lighting. You’ll feel secure if you’re here at night.