Minecraft wiki entry for Superflat_survival, associated text: If you are being nomadic, portals pose more of a problem for you. The good news is, you have several options. If you have enough obsidian, you could make new portals as you move, to have continual access to the nether. Building the portal from the Nether saves you a lot of walking (as each block there is 8 in the Overworld). Also, that way you always know where your portal is. To save obsidian, you can mine it from the corners of the portals you spawn, or go mine the whole portal and go back through to regenerate it. This creates renewable obsidian that you can use for more portals. Your other option is to gather lava from the Nether and turn it into obsidian where you are building your portal. However, this technique cannot be used in the Nether, as water evaporates, making obsidian impossible to create.