31. Four avenues opened out of the small cavern which the great rock stood in 32. There ' s an enormous cavern about 300 feet down , just below the cave entrance 33. Parameter inversion and constructing simulation of certain large underground cavern 34. Tunnel alignment with the boundary control facilities within a cavern system 35. For hundreds of years the statue had remained buried in an underground cavern 36. An artificial structure or excavation made to resemble a cave or cavern 37. I landed , and slopped through the timber and up the ridge and into the cavern 38. Stability ranking system of rockmass surrounding a large - scale underground cavern group 39. So , stability of rock mass around underground cavern grows more remarkable 40. New mexico and arizona 7 days antelope canyon , saguaro park , carlsbad cavern . . .
