Düden is a river named after the hole that swallows it. A düden, in Turkish, is a sinkhole, and this stream spends much of its life underground: it rises from the Kırkgöz and Pınarbaşı karst springs on the plain north of Antalya, runs briefly in the open, drops into the Bıyıklı sinkhole and travels for kilometres through rock before pushing back into daylight at Düdenbaşı. There it spills some twenty metres over a lip of travertine, into a cave the water itself has hollowed out — this is Upper Düden, and you can walk in behind the curtain. The stream then crosses the city, and at the Lara coast the ground simply stops: a cliff of pale travertine and a forty-metre drop into open Mediterranean. That is Lower Düden, or Karpuzkaldıran. The cliff is the river's own doing, built from lime it dissolved out of the mountains and left behind at the coast.
The two halves feel nothing alike. Upper Düden is cool and close: a shaded path along the gorge, then wet stone steps into the cave, where the falling water hangs across the opening as a green, roaring sheet. Lower Düden is a view from a distance, because there is no path behind the water and none down to the foot of the cliff. You watch it from the clifftop terraces of Düden Park or from the boats that leave Kaleiçi harbour, and on a bright day a rainbow stands in the spray where the river meets the sea. What you get, though, depends on what is left in the river. The same springs irrigate the farms of Döşemealtı, and in July 2017 the upper falls ran dry for about twenty days until the city installed pumps to lift water from the plunge pool back over the lip; a canal from the Kepez 1 hydroelectric plant now tops the flow up. In spring it is a torrent. By late summer it can thin to a white thread.