Will be there in a few hours, hopefully the TSA will allow a DC of lava buckets through the security gate.
A lava wall can make a million million rupeeses. So the lava wall. Excavate a 1 block wide trench as long as you want your lava wall to be to bedrock. It doesn't have to be linear, it's best if you make it meander hugely about the place so people don't know what direction they have to go to get outside of it, if any. This is inefficient, but good. Pillar jump up to the height limit with your dirt. Make a scaffolding to place your lava in. Keep it closed up so the lava doesn't fall outside where you want it to. Make a temporary dirt floor in the scaffolding, then place your lava once every 4 blocks. Once all your lava has been placed, break the floor, pillar dig back down, grab some popcorn, and watch the magnificent birth of a lava wall. You can also place lava walls adjacent to this if you want it more than 1 block thick. I recommend you make it so thick, nobody with a full inventory of lava resistance potions can survive. Time-consuming, but completely effective.
