Materials Needed:
Flint and steel (for fire)
26 Stone, Polished Andesite or Stone Bricks (your choice)
3 Iron Bars
5 Netherrack

Start by digging a hole 5 wide. Then fill in Netherrack. Place the stone blocks for the outline and another layer for the side outline (the longer part of the rectangle, both sides). Light up the netherrack and place the iron bars and you are done!

Design submitted by Frank