Located in Simi Valley, CA, Mountaingate Plaza serves shoppers from across the region. Shoppers can find this Community Center at NEC Los Angeles Ave. & First St.. Since opening in 1976, Mountaingate Plaza has been refreshed with a renovation completed in 2004. The mall spans 280,000 sqft. of leasable retail area and is home to around 60 stores. Ample parking is provided with 1,500 spaces available.