Ryongjong Pool is in Ryongjong-ri, Ryongyon County, South Hwanghae Province. The pool is 3 600 square metres in area and 50 metres long. The water volume of the pool scarcely changes. The daily water yield is 25 920 tons with the per-second gush being 0.3 ton.
The area is covered with limestone, and therefore the water of the pool is of calcium bicarbonate with a temperature of 17℃. The average annual temperature of the area is 9.7℃ with the average annual precipitation of 880㎜.
The name of Ryongjong Pool derives from the legend which has it that a dragon came out of the pool. For its large size and great economic value and academic significance, it is preserved as a natural monument.