Ok I still have high hopes we get the server for Minecraft so trying to stay ahead of the curve of learning. This is a "Netherworld" portal, hard to build need to be able to be around lava flow and figure out how to make buckets (3 iron bars) and collect lava, build a pit, put in lava, and then pour water over it. You need 20 blocks of obsidian, need a diamond pick to harvest and then flint and iron bar to make basically a striker to "fire it up" and you walk through to another world. I have gone through, collected stuff, and manged to get back.
This took some time but YouTube videos helped learning how to make obsidian if you can't find it naturally (and I didn't) and build the portal. I'm sometimes tired of the real world and wish I had a portal here!