You activate six underground explosives, which you plant as part of casting this spell, or that were abandoned after a long-forgotten war. Each is buried just below the ground at a point you can see within range. Each mine is 1” in diameter, and leaves the ground above it undisturbed and is undetectable to any creature without truesight or tremorsense until it is unearthed or detonates.   When a creature moves within 5 feet of a mine, it explodes. Each creature within 15 feet of the mine must make a Dexterity saving throw. A creature takes 4d8 thunder damage on a failed save, or half as much on a success.   When you cast this spell, you can designate any number of creatures. These creatures don’t activate the mines, but still take damage from them if another creature activates them.