Iron walls are a type of decorative block made from 2 units of iron bars. This block serves many different purposes, from decoration to defense against both ground mobs and dragons. Iron Walls are made out of 2 pieces of iron bar, and they serve as better protection than copper regardless of the situation.
Note: Iron is the fourth strongest material and is often found below various mountains or in Caves. It also takes the exact design of the "Metal Plates" block in CastleMiner.