巨穴

例句：

1. 1. The explorers found a huge cave with an underground river flowing through it.
   探险者们发现了一个地下河流贯穿的巨大洞穴。
2. 2. The giants were believed to have created this huge cave during their reign.
   据信巨人在他们的统治期间创造了这个巨大的洞穴。
3. 3. The cave was filled with stalactites and stalagmites, creating a unique natural wonder.
   洞穴中布满了石笋和石柱，形成了一个独特的自然奇观。