Iron Wall

 is a limited-time decoration that was released on October 4, 2016, as part of the Treehouse of Horror XXVII Event. It a craftable item. Each item crafted to levelling up the Construction Yard, additionally the first eight  the player with 20 MAG Points each.

Trivia

 * It can be rotated on all 4 directions.
 * It can be placed on grass, pavement, dirt, beach, boardwalk, pier, edge of boardwalk, edge of pier.