He sat down at the point where he'd almost hurled himself into the gorge, laughed, and tried to clear his head, and to get his bearings. The cliff, and the somewhat lower bluff across from it, were craggy, with great big shards and flakes of rock angling crazily into the air – and (by the way) exploding the Doctor's idea of how these rocks had been formed, because the grain of these rocks ran straight up and down. Obviously it was the remains of a giant, killed in some antediluvian rock fight, who'd died on his back with his bony fingers thrust up into the air.