Syri i Kaltër is a spring in southern Albania that nobody has reached the bottom of. From the rail above it the water is split in two: near-black indigo directly over the shaft, then a hard edge, then clear green over pale pebbles. That line hardly moves, because it marks a change of depth rather than a change of light. Everything in the pool arrived as rain on the mountain behind it, sank through the limestone and is being forced back into daylight here. It comes up at about ten degrees in every month of the year. You feel that before you see anything else: even at midday in August the air over the water is several degrees colder than the air you walked in with.
Almost nothing else about the spring holds still. An average year pushes out about six cubic metres a second; within days of heavy rain that can climb towards eighteen, and a single storm flushes sediment out of the cave system and leaves the pool brown for days. The blue only fires when the sun stands more or less overhead; in flat light you get a dull green. Swimming in the spring itself is not allowed, so people go down to the outflow instead. There the current spreads and slows until the surface lies glass-flat, cold and clear enough to show every stone on the bed while doubling the wooded slopes above it. Further down it runs shallow and quick over pale pebbles, with the path following it under the trees. Albanians tell the pool's story plainly. It is the eye of a giant serpent that ate its way through the villages until an old man drove a donkey loaded with burning straw into its path. The beast swallowed the fire, fled over the mountain to die, and its eye fell here and has been weeping ever since. Since the 1960s most of what weeps out of it has gone through hydropower turbines before reaching the sea. Divers have been fifty metres down the shaft and found only more water.