Like a mountain goat, he was agile, sure-footed, and he mounted the first bench without bending to use his hands.

The next ascent took grip of fingers as well as toes, but he climbed steadily, swiftly, to reach the projecting corner, and slipped around it.

Here he faced a notch in the cliff.

At the apex he turned abruptly into a ragged vent that split the ponderous wall clear to the top, showing a narrow streak of blue sky.
At the base this vent was dark, cool, and smelled of dry, musty dust.
It zigzagged so that he could not see ahead more than a few yards at a time.

He noticed tracks of wildcats and rabbits in the dusty floor.