For my nether rail I made a 2x2 tunnel. on one side there is a rail with slabs on the roof so no pigmen will get on the rail to stop you. It is 1.5 blocks tall so you can ride a cart but not walk on it. The other side is for walking on if you get stuck or something. I made it down to bedrock so no one can see it on the map. The entrance is a few hundred blocks away from spawn so it's harder to find.
when you guys say you made it to the bedrock, that means that most of it is under lava? if so, lots of work involved in there..
I think they meant all the way at the top, just under the bedrock ceiling. Most of the nether rail systems I've seen have been up there, around "Y" level 120 or so. I dug a tunnel at the bottom, and didn't make it straight, it has a few jigs and jogs in it and being mostly near the bottom it doesn't show up on the map as much. Like others have said before, hiding it behind false walls shouldn't be your entire security. Obscurity is only a bare minimum first step and you should expect it to be found. What you do and how you build it is up to you and how much time/effort you want to put into it. However, expect it to be found, just keep an eye on it for griefing.
Trick to hiding tunnels in the nether is to leave one block of air below bedrock then cover the tunnel with netherrack. I've been redoing our tunnels and they do disappear from the map when this is done.
I've made few public railways called "Quartz Express" and there was never a major griefing. The entrance is always hidden and at least 50 blocks away from the nether side portal. The end of the track is far out and not near any base / portal. There are several stations and many branches from the track and one would need to spend a lot of time finding which one really leads to a base. The most severe griefings that I've experienced in the past were from kids that just "got diamond" and thought they are somehow privileged and higher class than non-supporters. But my impression is that EMC did mature a bit and that such griefings occur less often than before. That is also due to /map hide being available to everyone. Before that, people would occasionally travel 30k+ blocks through overworld just to see what we're doing that far out there. Of course, the griefing potential was high. My experience is that the majority of griefing is not planned in advance, but is just kids fighting over anything and testing the limits. One time my mining base in the wastelands was griefed and griefers explained that "it was so pretty that they thought it was generated and not player-made"
And thus an excellent reason to destroy it??? I do not understand this behavior, what idiots! *hatin' on the griefers of the world*
