The Iron Shield is an item that has featured in a couple of Zelda titles. It is also known as the L-2 Shield.
 The Legend of Zelda: Oracle of Ages
In Oracle of Ages, the Iron Shield is found after obtaining the Mermaid Suit at the southwest corner of Crescent Island where Link has been marooned and his possessions stolen by the Tokay. He then sets out to reclaim his items from the thieves around the island. One said thief resides in a cavern that may only be reached via use of the Mermaid Suit. The thief does not return the Wooden Shield, however, and instead presents Link with the Iron Shield.
 The Legend of Zelda: Oracle of Seasons
In Oracle of Seasons, the Iron Shield is not an obtained item, but rather it is an upgrade to the Wooden Shield. Once Link has acquired one piece of Hard Ore, he can then travel to Subrosia and the Subrosian Smithy will use the ore to upgrade your shield to the Iron Shield. Having said this, the shield may also be purchased in Horon Village.
 The Legend of Zelda: Skyward Sword
The Iron Shield is the first part of the second line of shields that become available to Link in Skyward Sword. It can be upgraded first into the Reinforced Shield, and then the Fortified Shield. Although it provides a greater durability than the wooden line of shields and doesn't disintegrate from fire attacks, it does have a vulnerability to electricity and can be destroyed if attacked by Thunder Keese. It is purchased at the Bazaar in Skyloft. It can also be upgraded there by taking it to Gondo at the Scrap Shop along with two pieces of Eldin Ore, two Monster Claws and two Ornamental Skulls and paying a small fee for the Reinforced Shield.