Minecraft wiki entry for Secret_door, associated text: This entrance can be a bit dangerous, especially if the player is low on health. As shown in the schematic, after the player goes into the lava, they sink through, fall past the signs, and into the water. This design can be expanded or shrunk as needed, however it may be tricky to make it more than 2 blocks wide. To ensure your health will not run out with your difficulty settings and armor, it may be a good idea to test it for the first time with Fire Resistance. Some good hiding places for this: a beat up house with a single bucket of lava on the floor; a natural lava pool; in a decorational lava pool.