Kızören Obruğu

Kızören Sinkhole is a giant collapse lake about 70 kilometres northeast of Konya, within Karatay district, a few kilometres north of the Konya to Aksaray road. The steep limestone walls that appear suddenly in the middle of the flat steppe, and the deep blue water at the bottom, offer a view that is hard to believe on first sight. The lake is described as the largest known sinkhole in Turkey. Obruk is the name for a vertical pit that forms in karst terrain when the roof of an underground cavity collapses and opens to the surface. Kızören Sinkhole lies on a limestone plain with many such pits, which is why it is called the Obruk Plateau. The plateau stands at roughly 1000 metres, surrounded by steppe that has largely been turned into fields. Most sinkholes in the region are dry, while Kızören is one of the rare ones that still holds a large body of water. Sources give different measurements for the sinkhole, and the difference may depend on the year in which they were taken. Turkish Wikipedia gives its diameter as 228 metres and its total depth as 171 metres, of which 145 metres is water. The Showcaves website, which publishes on caves and karst, states that the pit is about 180 metres long and 150 metres wide, with the water about 25 metres below the surface and 145 metres deep. What both sources agree on is that the water lies tens of metres below the surface and that the lake is very deep. The water seen in the sinkhole actually marks the level of the groundwater in the region. The lake is fed by groundwater and shows a level change of up to 5 metres during the year. Heavy pumping for irrigation has lowered the lake noticeably, and the drop between 1996 and 2006 was measured at about 10 metres. Because its water was the cheapest source of fresh water nearby, the State Hydraulic Works once installed a pump on its southern shore to supply drinking water to local people. Pumping from the lake for farm irrigation and household use was later stopped. The fact that Çatalhöyük, one of the oldest settlements in the world, lies only 64 kilometres from here is a reminder that water has stood at the centre of life on this plain for thousands of years. As the groundwater around it is drawn down, the pressure on the walls of cavities that used to be full of water disappears, and these cavities can collapse. Showcaves explains that new collapses are increasing in the region for this reason. Geologists from Selçuk University also note that the area from just south of Kızören to Karapınar holds many recently formed sinkholes alongside old ones such as Meyil and Çıral. So follow the open paths when approaching the rim, and do not go right to the edge where there is no railing. The lake and 127 hectares around it were declared a Ramsar site in 2005. No living creatures have been found in the lake, yet the rim around it and the blue water make a striking picture in aerial photographs. The area is also protected as a strictly protected sensitive zone. On the western rim of the sinkhole stands the Obruk Han, an Anatolian Seljuk caravanserai. With no inscription, its founder and architect are unknown, and specialists date it to the first half of the 13th century. The han takes its name from the sinkhole beside it and drew its water from here while it was in use. On this road, where caravanserais were spaced 30 to 40 kilometres apart to match a day's march of a caravan, the Obruk Han is one of the links in the chain between Konya and Aksaray. After a long period of neglect, the restoration and landscaping of the han were later completed. Kızören is easiest to reach by private car from the Konya to Aksaray highway, and travellers heading for Cappadocia also stop here. The lake water was long thought to be still, but it is now known to flow slowly underground towards other lakes. The wind on the steppe can be strong, so remember to bring a warm layer and water. If you visit it together with Zazadin Han, which lies closer to Konya on the same road, you see both the architecture of the Seljuk caravan route and the value of water on this plain in a single day.