Iron door can be made of the six ingots of iron. They should be placed on a workbench, taking two adjacent vertical completely. Iron ingots can be obtained from iron ore. It is easy to find in any cave below level 64. To mine iron ore, you can use stone, iron, gold or diamond pickaxes. To from a block of ore to ingot, it is necessary to melt it in the oven. Iron ore is one of the most common resources in the world of Minecraft.
Iron doors can't be destroyed by aggressive zombies on the higher difficulty levels, sometimes they can survive the detonation of a creeper. This door cannot be opened by clicking the right mouse unlike wood. Protected door requires the use of auxiliary devices such as buttons, pressure plates or levers.
In Minecraft there is a similar electricity — red dust. Experienced players using this technology to build calculators, complex traps and even computer processors. Buttons, levers, stretching and pressure plates types of switches that activate a Redstone signal.
In the elementary variant it is enough to set one of the switches close to the iron door to open it. The button or lever can be placed on a nearby vertical surface to which attached the door. The pressure plate need to be placed directly in front of the door.
If you want to make more complex the scheme, you need to get the red dust. It can be extracted from the red ore, which in large quantities is mined in deep caves. Its maximum concentration can be detected between levels 1 and 16. To mine ore you need an iron or diamond pickaxe. In a few minutes you can collect a lot of red dust, because from one block of ore falls from four to five units. But at this depth it is necessary to act with maximum caution in order not to fall into the lava lake.
Button, lever or pressure plate you can combine with the door chain red dust. Place the switch at a distance of not more than eight blocks from the door and pull to her a trail of red dust on horizontal surfaces. For safety a chain of red dust, you can close other blocks to not accidentally destroy. If you want to place the switch on off eight blocks from the door, you will have to make a repeater. It allows you to transmit Redstone signals over long distances.