I finished the storage room to my island for the server i'm on and it took a while trying to get it right, but I may alter it a bit. But this is a structure that is going to be hidden in a floating island, with 2 trap floors doors and a 4 digit combination lock to get in the storage room.

as I hid all the lighting and the lowest BL is 8 so no mob spawns. so that was a bit challenging and trying to make it look good.

I just love this idea. and its just a great way to make a storage room.