The credit for the fact that these caves are still intact after all this time goes to the nature of the rock, which is very hard Tulan Mountain agglomerate rock. Its particular resistance to erosion has permitted the caverns to avoid collapse.
這些洞歷經這麼長的時間還能保存完整，得歸功於岩質堅硬的都蘭山集塊岩，其耐蝕的特性，讓這些洞至今仍未崩毀。