Minecraft wiki entry for Nether_hub, associated text: 1 Introduction
1.1 Materials
2 Steps
2.1 Easiest and cheapest method
2.2 Example
2.3 More precise method
3 Comparing coordinates
4 Multiple Portals
5 Safe Travels
5.1 Tunnel system
5.2 Nether roof
5.3 Map
6 Video
7 See also