Minecraft wiki entry for Furniture, associated text: Make a huge fireplace 3×3 with a campfire/netherrack, and then add a fence at the side (it'll need to be a nether brick fence if you're using netherrack) and progress it to the center. It should be 3 blocks from the ground. Now, descend it to almost the fire level (2 blocks away) and add a cauldron to the nether brick fence. Add water in and it's done! Fun if making witch houses.