There are a lot of designs for hidden trap doors out there, allowing you to enter your undergroud lair. But how, I asked, is one supposed to get back up and out of that hole. Why with this of course, it is my first design for a trap door style exit which is completely hidden against the groud from the surface. You can think of it as a mini lift out of your base.

The design is a lot more complicated than you might expect as pushing the block you are standing on up to the sufrace of course leaves a vacant block where that one once was, so a piston tape is needed to replace this block each time, my design uses a piston tape with 5 blocks going round in a cycle.