Minecraft wiki entry for Shelters, associated text: Using trapdoors, some redstone, and switches, a simple drawbridge can be made. Dig a moat around your base and make sure it is too long to jump across. Now, make short walls next to your entrance. Depending on whether you have a single door or double door, you will have to use one row or two rows of trapdoors respectively. Run redstone next to the trapdoors and connect them to switches inside your base, then cover up the redstone walls. This prevents mobs from getting close to your door while you are inside your base, but the bridge has to be left open while outside your base, otherwise you'll have to find another way back in. Alternatively, you can make a T Flip-Flop gate and place another switch outside your house to trigger the drawbridge from anywhere.