Finally they emerged from its darkness into one of the most novel plazas, or squares, of the world. It was surrounded by buildings of several stories in height, but very few of them had any doors, while the tiny windows of the lower stories were placed high up, beyond a man's reach. On the flat roof of the lower house, or first story, a second house was built; but it was so much narrower than the first as to leave a broad walk on the roof in front of it. Above this second house rose a third, fourth, fifth, and often a sixth, each one narrower than the one beneath it, so that the whole looked like a gigantic flight of steps.