This is one of my early redstone-projects.

The walls of the staircase are made of "double stone slabs", with one single lever at the upper floor of the shaft all stairs can be pulled back into the walls. The shaft is 65 blocks deep but it can get even deeper or less deep very easy!

Everything was handmade, I only used "To Many Items" to get enough material. after finishing the project I just replaced every material (dirt, gravel, ores) with stone.