南天门

当前我们所处位置的前方，视野突然变得狭窄，形成了一种独特的“门状”结构，我们将其称为“南天门”。南天门顶端的钟乳石以弯曲的形态生长，这在地质学上被称为“弯曲石”。关于弯曲石的形成，它与洞内的风向紧密相关。由于洞内空气存在南北对流现象，且风向会随着季节的更替而发生变化，这种变化导致了洞顶滴水位置的偏移。进而，水中的矿物质在滴落过程中发生不定向的沉积，最终形成了我们所见的弯曲石。

In front of our current location, the view suddenly becomes narrow, forming a unique "gate-like" structure that we call the "South Gate of Heaven." The stalactites at the top of the South Gate of Heaven grow in a curved shape, which is geologically known as "curved stone." Regarding the formation of curved stone, it is closely related to the wind direction within the cave. Due to the phenomenon of north-south air convection in the cave, the wind direction changes with the alternation of seasons. This change causes a shift in the dripping water position from the cave ceiling. As a result, the minerals in the water deposit irregularly during the dripping process, eventually forming the curved stone that we see.