In Crimea there are a popular tourist sites such as ancient "cave" city-fortress: Chufut-Kale, Tepe-Kerman, Mangup Kale and others. Particular attention is drawn to the city-fortress of Chufut-Kale under Bakhchisarai. This city is the historical territory of the Crimean Karaites. The fortress is built on the isolated plateau where no natural outlets of underground water. In the past there were more than a thousand citizens and they lived there until the middle of the XIX century.

Despite the lack of natural ground water exits the city lived hundreds of years. Karaite elders remember the delivery of potable water to the castle from a nearby source. For technical purposes were carefully and skillfully collecting atmospheric precipitation. However from legends have been known that during the siege the water taken from a hidden hydraulic system and information of it was a military secret. Even when the castle lost its defensive significance this mystery Karaites passed down from generation to generation.

Based on information written and oral sources cavers began to search. Theoretically the water should be found in a geological fault in the Pendzher-Isar. Here was focused work. A slight deepening under the growing tree was beginning of Chufut-Kale well! It was in August 1998. During 3 years blocks of rock and soil were removed from the well at first by hands and then by use mechanisms. In total were involved more than forty people. Work on the well clearing were done by employees of the Speleotourism Center.

At the 25-meter deep explorers discovered a side entrance full of stones that gently rising up. Topographical survey showed that the upper end of the gallery comes to the surface. After clearing of gallery it turned out that the gallery starts from the basement of battle tower which probably belonged to the first line of defense of a fortified city. Earlier about this line of defense archaeologists did not know.

Next in Chufut-Kale well at a depth of 27 meters appeared spiral stone slope which led to the large reservoirs at a depth of 40 meters from the surface. The water from the large cracks in the walls of Chufut-Kale well came in one of the reservoirs then was poured into another reservoir and next was taken for use. Now the cracks silted and water are practically not goes. On the walls of the lower rooms were found niches for lamps. After clearing the bottom of the well - the total depth of the well was 45 meters.

Who and why was built that complex and huge system? The basic version - speleologists opened the largest in the Crimea hydraulic structure which served for water supply during the siege of the fortress.

It was done electric lighting of all parts of the system. The unique ancient structure is transformed into an interesting excursion attraction.

On 20th of March 2002 just a few meters from the entrance to Chufut-Kale Well has been found a huge treasure of medieval coins. On this day the staff Speleotourism Center were clearing the entrance to the underground structure. When cleaning the moat at a depth of 40 cm was accidentally discovered an ordinary ceramic pot filled with small silver and gold coins. The unique treasure was transferred to the Crimea Museum in Simferopol and is now available for public view.