Here is another installment of exTRAPaganza, our Thursday over-the-top trap series.
A spiral staircase ascends hundreds of feet up from a small island in the middle of a lava lake, ending in a small landing with a chest. The chest has a single switch to open. When the switch is toggled, the switch opens, but the magic staircase, landing, and island below vanish. The switch turns on an anti-magic field in the entire area. So, would-be thieves get to fall 500feet down into a lava lake.