When you are weary of the noisiness and crowdedness of city life， and yearn for a place of peace and calm， the Benxi Water Grotto （洞） offers a tranquil experience which will almost rekindle your senses. 
A 35-km drive to the east from Benxi City on Liaoning Province will take you to the Benxi Water Grotto Scenic Spot where the world’s largest Karst water cave is found.  
A key scenic site， it is also listed as a member of the World Touring Grotto United Association. The water grotto， formed millions of years ago， is 5， 800 meters long， of which a 2，800-meter section is open to visitors. The most open area is 38 meters high and 50 meters wide， with a space capacity of 400，000 cubic meters. The water in the cave has an average depth of 1.5 meters， with water at the deepest section measuring 7 meters high. Ventilation in the grotto is good， and there is a constant flow of water throughout the year. About 10，000 tons of water a day rushes through the grotto and into the Taizi River bordering it.  
The temperature within the grotto is a pleasant 12℃，comfortable I winter and cool in summer. At the peak of summer， the temperature differences within and outside the grotto is so huge that water vapor at the grotto mouth forms a layer of mist. On a cold winter morning， crystal clear frost can be spotted on trees outside the grotto. 
Secretary General of the World Touring Grotto United Association Kamiya Aik was full of praise for the grotto after a tour of the natural wonder. “The Benxi Water Grotto is the longest underground river which can be visited by boat that I have ever seen. How beautiful and wonderful it is!” 
Shaped like a half moon， the mouth of the grotto is 28 meters wide and 20 meters high. As you enter the cave， you will be greeted in the grand “guest welcoming hall” which can house 1，000 people. Here， you can board the rubber boat for a leisurely ride through seven cave palaces interspersed with three gorges. Look up as you enter the Lotus Gorge， and you will see at the top of the 100-meter gorge that there are numerous stalactites resembling inverted lotus flowers， as well as grand clocks on the wall. On the banks on both sides， layers up on layers of stalactites formed along the walls create a swirling Milky Way.

The uniqueness of Benxi Water Grotto is that （）.