Alisadr Cave

Alisadr Cave is one of Iran's lake caves and one of the few water caves in the world. It also has the longest navigable boating route inside a cave anywhere in the world. The cave is located in the Sari Qeyeh highlands near the village of Alisadr, in Kabudarahang County, Hamadan Province. The cave lies at an altitude of 2,100 metres above sea level. Its interior has winding corridors and numerous passages. The cave is 11 kilometres long, but because the route is difficult, only 3 kilometres of it have been explored. A series of streams has formed a large lake inside the cave, so the only way to reach its depths is by boat. Alisadr Cave is one of the tourist attractions of Hamadan Province.

What sets Alisadr Cave apart from other water caves in the world is how easy it is to use its water channels. Thanks to their width, you can move through them comfortably and pass through them in ordinary boats. According to the same report, the Alisadr limestone formation contains many fractures, about 2 to 3 per metre. In addition, a number of funnel-shaped holes can be seen at intervals of 1 to 2 metres. Both features allow surface water to seep in quickly. Moreover, the water in Alisadr Cave reaches a depth of 14 metres at its deepest point.

Alisadr Cave was formed entirely by natural processes, without any human intervention. As for how the cave came into being, rainwater combined with carbon dioxide in the air to form weak carbonic acid. As this acid seeped into the limestone ground and reacted chemically with it, it produced an unstable compound called calcium bicarbonate. Because calcium bicarbonate dissolves in water, it creates hollow spaces inside thick layers of limestone. Over millions of years these spaces expanded and joined together, and in this way Alisadr Cave, this astonishing masterpiece of nature, was created deep within the earth.