Turner painted night scenes throughout his career. Although painted by night, the two castles on opposite banks of the Rhine can be seen more clearly here than in his daytime studies. The smaller Wörth Castle is just sketched in green watercolour next to the falls, while Laufen Castle shines in the moonlight on the hill to the right. Turner has created ripples in the foreground by removing ribbons of wet wash with a dry brush. Unusually, he inscribed this work at lower right: Falls of the Rhine/1841.