You step off the bus onto a strip of basalt and spray—the roar arrives before the falls come into view, a low, steady percussion that makes pockets of air taste like cold metal. Goðafoss spreads out in a white crescent, water pushing itself over 12 meters of volcanic lip and throwing up a fine mist that lifts and drifts like a live map of the river. Cameras click; a guide points toward the river’s bend and explains the old story about chieftains and the year Iceland embraced Christianity—stones of the pagan gods said to have been sent tumbling into this very current.