Behind them he could see the mouth of a cave; the six months' old growth of vegetation about the entrance gave clear indication as to the time which had elapsed since a human foot last disturbed the solitude.
A few vigorous blows with the stick cleared away obstructing plants and leafy branches.

The sailor stooped and looked into the cavern, for the opening was barely five feet high.

He perceived instantly that the excavation was man's handiwork, applied to a fault in the hard rock.

A sort of natural shaft existed, and this had been extended by manual labor.

Beyond the entrance the cave became more lofty.