Rivers, a waterfall, a cave and travertine walls.... What's more, all this natural beauty is concentrated in one place. Not only that but the rivers at Yerköprü flow one on top of the other, just like a two-level highway.

Arising in the Geyik Mountains, the Gökdere collects the waters of Taşeli highland before flowing through the townships of Bozkır and Hadim districts in Konya. Standing erect like soldiers at roll call, an emerald green swath of poplars lines its banks. Winding tortuously through high wide valleys, it arrives at Yerköprü 23 kilometers east of Hadim. Here it goes underground, emerging again some 50 meters further on. But the spot where it resurfaces is inside a cave. Some 30 meters above, a second river arises from a source in the hills and begins to flow in the same direction as the Gökdere but above it. Forming a 30-meter-high waterfall some 500 meters later, it plunges down into the Gökdere. The two rivers merge to form one of the main tributaries of the 296-km-long Göksu River. Flowing past the hydroelectric plant at Yerköprü on the Göksu, the river surges on through Ermenek and Silifke, eventually emptying into the Mediterranean.  

The term Yerköprü (literally, Landbridge) is used for the geological formations that are caused when a river goes underground and then emerges again some distance later. To spelunkers they are known as siphons, formations in which the water sinks underground to emerge at another spot. A 6-person team from the Society for Underwater Research and the Underwater Exploration Group of Middle East Technical University navigated the Yerköprü siphon on 16 September 2001. Not only that, they also discovered an underground branch of the Karasu, a small stream. Inside, the cave is covered with stalactites large and small. The trunks and  branches of the trees which are uprooted and swept away when the waters swell in spring also wash up inside the cave. 

Swelling in spring, the waters sometimes rise so high that they overflow the cave and merge with the waters of the Karasu. The weight of the water however leads to the formation of depressions at the cave mouth.

Waterfalls large and small
The way Yerköprü Cave was formed is also quite interesting. Following a landslide on one of its slopes, the valley of the Göksu was stopped up, forming a natural dam. Later, the Karasu, which has its karstic source in the slope on the valley's right side, spread out over the landslide mass creating a crust of travertine. In time the Göksu formed a tunnel  below this natural dam, giving rise to today's Yerköprü Cave. Meanwhile, as if to crown the entire scene with glory, the karstic source of the Karasu produced waterfalls that plunge from a height of 30 meters into the bed of the Göksu from a travertine platform at the entrance and exit of the cave.

Due to its calcareous properties, the Karasu deposits a white sediment of calcium and carbonate precipitates along its length to form travertines similar to those at Pamukkale. The stream's waters are also believed to be useful in treating certain diseases of the skin. Thanks to the watermills that stood on the tributaries of the stream until the advent of electricity, flour was milled here in the neighboring settlements, such as Karaman and Konya, and it is still possible today to come across abandoned millstones and the walls of collapsed mills.

Located near the border between Antalya province and the Konya province township of Hadim, Yerköprü in the valley of the Göksu is reached by a journey of 116 km through the villages of Kayaağız and Habiller on the Konya-Karaman road. It can also be reached via Mersin-Silifke to the Göksu valley where it is located.

Visitors can tour both the top of the cave and its entrance and exit. Any exploration inside the cave requires special training in spelunking. If you visit here you will get wet, so be sure to come prepared.

Registered as a national monument
Registered as a Natural Monument by the Forest and Environment Ministry's Department of Nature Conservation and National Parks on 3 May 2008, Yerköprü was declared a protected site. The natural beauty of the Yerköprü basin, a geological formation unique in the world and host to day-tours mainly from Konya and Karaman, charms all visitors. Leaving those who see it gaping in disbelief, this natural wonder, where travertines and waterfalls, rivers and caves exist side by side, opens the door to a great world of imagination.