Miscellanies 6.3.33

So from every place from which it could be seen, the fire was beheld blazing by all of them round about, as though they were encamped around it, so that the descent was not a local one; for God is everywhere. And those who have compiled histories say that near the island of Britain there is a cave lying under a mountain, with a chasm at the summit; when the wind falls into the cave and breaks against the hollows of the cavity, a sound is heard like cymbals struck in rhythm. And often in the woods, too, when the leaves are moved by a sudden gust of wind, a sound strikes the ear like the song of birds. And those who have written Persian histories relate that in the upland regions, in the country of the Magi, three mountains lie in a row on a long plain. Those who travel through the place hear, when they come to the first mountain, a confused noise, as of many tens of thousands shouting, as in battle array; when they reach the middle one, they perceive a din at once louder and clearer; and at the last they hear men singing a paean as if victorious. The cause of every echo, I think, is the smoothness of the places and their cave-like character. For the air that enters, being thrown back and moving again into the same space, sounds more violently.