Minecraft wiki entry for Pillar_jumping, associated text: Removal can be accomplished with minimal effort if the pillars are made with a gravity-affected block such as gravel. The method involves placing a torch (or other similar blocks such as fences or signs that have the same effect) on the ground, then directly above it placing a non-gravity-affected block such as dirt, and then building the column with the gravel on top of that block. When the pillar is no longer useful, the dirt can be removed, which will cause the gravel to fall onto the torch. This will cause all the gravel to rapidly disintegrate. However, doing this on a public multiplayer server can be dangerous, as another player can quickly kill you from fall damage if you are on top. You can also build it without the torch and dirt, by destroying the bottom block by hand and quickly placing a torch underneath the tower, and the blocks will appear as items the same way as previously.