Minecraft wiki entry for Mining, associated text: Caves often contain dead-end passages and shafts, or masses of gravel and dirt blocking the way. Many of these dead ends are actually thin barriers that, if removed, reveal continuing passages, sometimes into entire adjacent cave systems. 'Drifting' is a term for simply searching for adjacent caves by digging beyond apparent dead ends. Drifting can be effective in finding dungeons if there are mob sounds audible at a dead end. Once players can make pistons, those can also help detect nearby caves, even through rock: Set one up facing against a wall, and power it with a lever or redstone torch. If there's an open space within 12 blocks ahead of the piston, it will push a hole into the wall.