Dikes of this volcanic stone crossed each other or ran in long parallels, presenting forms of fortifications, walls of buildings, ruined lines of aqueducts.

The sandstone and marl had been worn away by the departed river, and by the delicately sweeping, incessant, tireless wings of the afreets of the air, leaving the iron-like trap in bold projection.
Some of these dikes stretched long distances, with a nearly uniform height of four or five feet, closely resembling old field-walls of the solidest masonry.

Others, not so extensive, but higher and pierced with holes, seemed to be fragments of ruined edifices, with broken windows and shattered portals.

As the trap is columnar, and the columns are horizontal in their direction, the joints of the polygons show along the surface of the ramparts, causing them to look like the work of Cyclopean builders.
The Indians and Mexicans of the expedition, deceived by the similarity between these freaks of creation and the results of human workmanship, repeatedly called out, "Casas Grandes! Casas de Montezuma!" It would seem, indeed, as if the ancient peoples of this country, in order to arrive at the idea of a large architecture, had only to copy the grotesque rock-work of nature.

Who knows but that such might have been the germinal idea of their constructions?
Mrs.Stanley was quite sure of it.
In fact, she was disposed to maintain that the trap walls were really human masonry, and the production of Montezuma, or of the Amazons invented by Coronado.
"Those four-sided and six-sided stones look altogether too regular to be accidental," was her conclusion.