Here's my take on a hallway. Not sure if anyone else has come up with this idea but I've never seen this in game or on the forums. This can be built of any length but it should always have the team door equal with the bottom layer of trapdoors. For this picture, I didn't include a stone background but it is preferred as it will hide the spikes from your enemy until it is too late (hopefully). You could also dig deeper and put spikes beneath the bottom layer of trapdoors to provide even more pain. :) The only problem with this build would be repairs. Enemy builders will make short work of this trap and as such a good supply of wood will be needed to maintain any damage it receives.