Minecraft wiki entry for Things_to_do_when_bored, associated text: Dig down to bedrock and build a tower of TNT all the way up, with layers of solid blocks in between(due to TNT becoming an entity when lit). Dig a quick hole down the side for access purposes, then light it all the way up! You can blow up a village and harass the villagers. Note: make sure you're not on other's servers, these actions may be considered griefing.