A outlined illustration of a vast underground cavern illuminated by towering crystalline formations in shades of blue, purple, and teal. Stalactites hang from the vaulted ceiling, dripping glowing water into shallow pools below. A narrow stone bridge spans a subterranean river that winds through the cave, its surface reflecting the crystal light in shimmering patterns. Along the cavern walls, patches of luminescent moss emit a soft green glow. Wooden scaffolding and minecart tracks suggest recent exploration, with a few scattered barrels and lanterns near the entrance. The atmosphere is mysterious and awe-inspiring, with deep shadows contrasting the brilliant crystal formations.