hello, everyone who got all exited about going to the nether when your obsidian frame would light on fire, but not activate, and are now scaning different minecraft sites, looking for answers. here they are: it needs to be a 5 block tall, 4 block wide rectangle of obsidian, hollow inside the frame, making a 3 block tall, 2 block wide hole in the center. the corner peices to the rectangle are not nessasery. to activate it, light the inside of the frame on fire with flint and steel. I know all this because yesterday, some website I was on convinced me it only had to be two blocks tall, and it did not work. if you dont want to go to all the trouble to get enough diamonds to make a diamond pickaxe, all you need is a bucket and flint&steel. you just need to find lava, take a block out and harden it to see if it turns to obsidian, and if it does, you can use it to pour into a mold of the portal frame, and harden it with water. then light it with the flint and steel.