The Tristaina Lakes, the Estanys de Tristaina, are three glacial lakes stacked on a rock staircase at 2,300 metres above the Arcalís ski resort in the parish of Ordino, in Andorra, spilling one into the next, and they are walked in a loop of two hours and seen together only from the ridge, where a steel ring on the crest is a working sundial. The lakes are not pools in a stream but separate hollows that the glacier bit into the granite wherever it was weakest, riding over the harder steps between, so that Estany Primer comes first, the smallest and bluest, ringed with grass and a few wind-bent pines, then the middle and the highest under the peaks of the French border; the path climbs from one to the next over the rock steps and up to the crest, where the Tristaina sundial stands, a ring of steel with a mast leaning through its centre aimed at the pole star, and stepping onto it the ground drops away, the three lakes in their bowl on one side and the French Pyrenees on the other. Marmots whistle from the boulder fields, an animal that disappeared from the Pyrenees around 15,000 years ago and was brought back last century.
The loop is usually walkable by late June, when the ice has gone off the basins and the meltwater is topping them up from the cirque wall, with old snow still lying in the shaded gullies, and the alpenrose, the low pink rhododendron of the Pyrenees, flowers across the slopes below the lakes in the first weeks after the snow lets go. From late September the grass and bilberry heath turn copper and rust and the water looks almost black against them, and from December the lakes freeze and the bowl fills in with snow, so that on snowshoes the staircase reads as one white slope with nothing to show where the deep basins lie. The Tristaina lakes are three steps of water the ice left, and the ridge is where they are counted.