eat bowlders. And on the far side of the valley
lay what appeared to be a mighty city, its great walls, its lofty
spires, its turrets, minarets, and domes showing red and yellow in the
sunlight. Tarzan was yet too far away to note the marks of ruin--to
him it appeared a wonderful city of magnificent beauty, and in
imagination he peopled its broad avenues and its huge temples with a
throng of happy, active people.

For an hour the little expedition rested upon the mountain-top, and
then Tarzan led them down into the valley below. There was no trail,
but the way was less arduous than the ascent of the opposite face of
the mountain had been. Once in the valley their progress was rapid, so
that it was still light when they halted before the towering walls of
the ancient city.

The outer wall was fifty feet in height where it had not fallen into
ruin, but nowhere as far as they could see had more than ten or twenty
feet of the upper courses fallen away. It was still a formidable
defense. On several occasions Tarzan had thought that he discerned
things moving behind the ruined portions of the wall near to them, as
though creatures were watching them from behind the bulwarks of the
ancient pile. And often he felt the sensation of unseen eyes upon him,
but not once could he be sure that it was more than imagination.

That night they camped outside the city. Once, at midnight, they were
awakened by a shrill scream from beyond the great wall. It was very
high at first, descending gradually until it ended in a series of
dismal moans. It had a strange effect upon the blacks, almost
paralyzing them with terror while it lasted, and it was an hour before
the camp settled down to sleep once more. In the morning the effects
of it were still visible in the fearful, sidelong glances that the
Waziri continually cast at the massive and forbidding structure which
loomed above them.

It required considerable encouragement and urging on Tarzan's part to
prevent the blacks from abandoning the venture on the spot and
hastening back across the valley toward the cliffs they had scaled the
day before. But at length, by dint of commands, and threats that he
would enter the city alone, they agreed to accompany him.

For fifteen minutes they marched along the face of the wall before they
discovered a means of ingress. Then they came to a narrow cleft about
twenty inches wide. Within, a flight of concrete steps, worn hollow by
centu