Start a new world and the foot of a waterfall has a plunge pool worn into the ground: level, a few meters deep, with the creek spilling out over its sill. Before, the water lay on the slope at the foot as dark shards. A fall that drops into a lake keeps its pool too.

The pool reads as clear teal water with a rounded shore, green-blue going dark with depth, and it lies level right up to the rock. Getting there took several rounds: the first pools tilted up the wall behind them like a slanted mirror, then read as a dark box, then carried dark spots every few meters. The foam at the foot sits on the pool’s own surface round the impact, with a pale green-blue glow of bubbles, and a soft haze of spray hangs over it.

Still rough: white streaks on the steep outlet below the pool, no wet band or foam line along the shore, and no boulders on the rim. The small falls that drop off a ledge beside a bigger one have no pool yet.