translation.en: But the weirdest thing about glacier caves is that the entire cave is moving, because it's formed inside a block of ice the size of a small city that's slowly sliding down the mountain.
translation.zh: 但是冰川岩洞最怪诞的是 整个岩洞是移动的。 因为它形成于冰块之中。 像一个小城市那么大、 慢慢从山上滑下的冰块。