How to Build a Piston Hallway in Minecraft

This is a tutorial on how to make a working piston hallway in Minecraft.

Add a row of 8 columns of sticky pistons, each with one space in-between them. Do the same for the other side, four blocks away.

Add 3 blocks of wool in an 'L' formation behind the pistons, then put a redstone torch on top.

Add a repeater to the start of the line of wool, just behind, then wire up with redstone, going up onto the wool, with every hollow block having a repeater.

Add a custom block in front of each piston, while filling in the gaps with any block.

Connect the wires to a lever, and pull the lever to activate the door.

You have completed your piston hallway.