壶穴（三窟袖月） Pothole (Three Caves Reflecting the Moon) 구혈(삼굴수월) 雨水使河水流量增加，带动上游的石块向下游流动。当石块遇上河床上岩石凹处无法前进时，会被水流带动而打转。久而久之将障碍磨穿，形成一圆形孔洞，称为壶穴。 以枯木潭为中心，上下各有一个因流水磨蚀而形成的孔洞，构成三个串连状的壶穴，被当地人称为“三窟”。从结构上看，这三个壶穴是受岩坎控制而形成的多层壶穴群，它们自上而下，由小及大再及小。若逢雨季，深窟如巨大的涡轮，翻腾旋转，声势如千军万马呼啸而来，其形态缭绕如水雾，宛若天庭仙女甩袖群舞，独具一格。每逢满月，三个壶穴映照着月亮的倒影，故称“三窟袖月”。 As the river flow increases, it carries stones from upstream downstream. When these stones encounter depressions in the riverbed and cannot move forward, they are spun by the water current. Over a long period, the obstacles are worn through, forming circular holes known as pothole. Centered around Kumu Pool, two cavities (one above and one below) are carved by the erosive force of flowing water, forming a chain of three interconnected potholes, locally known as the “Three Caves.” Geologically, these potholes constitute a multi-tiered pothole complex shaped by rock steps, arranged from top to bottom, scaling from small to large and back to small. In the rainy season, the deep cavities churn like mighty turbines, roaring like thousands of galloping horses charging forth, with their misty swirling resembling celestial fairies twirling their sleeves in dance. On full moon nights, the three potholes shimmer with the moon’s reflection, hence the name “Three Caves Reflecting the Moon.” 빗물이 강물의 유량을 증가시켜 상류의 돌멩이를 하류로 흐르게 한다. 돌멩이가 강바닥의 암석 오목한 곳을 만나 전진할 수 없을 때, 물살에 이끌려 맴돈다.오랜 시간을 거쳐 장애물을 갈아 뚫어 둥근 구멍을 만드는 것을 구혈이라고 한다. 고목담을 중심으로 상하에 각각 흐르는 물이 마모되어 형성된 구멍이 하나 있는데, 세 개의 직렬 모양의 구혈을 구성하여 현지인들에게 ‘삼굴’이라고 불린다. 구조적으로 볼 때, 이 세 개의 구혈은 암벽의 통제를 받아 형성된 다층식 주혈군으로, 그것들은 위에서 아래로, 작은 것에서 큰 것에서 작은 것으로 다시 형성된다. 만약 장마철을 만나면 깊은 동굴은 거대한 터빈처럼 뒤척이며 회전하며 성세는 천군만마가 휙휙 소리를 내며 다가오는것과 같으며 그 형태는 물안개처럼 감돌고있으며 마치 천정선녀가 소매를 휘두르는 군무처럼 독특한 격식을 갖고있다. 만월이 되면 세 개의 구혈에 달의 그림자가 비치기 때문에 ‘삼굴수월’이라고 부른다.