Tenochtitlan means "The Stone-cactus place;" and the Aztec picture-writings express its name by a hieroglyph of a prickly pear growing on a rock.

Putting this history out of the question, the Aztecs had excellent reasons for choosing this peculiar site for their city; but these reasons were not equally valid in the case of the new invaders.

For them the surrounding salt-water was not needed as a protection, and was merely a nuisance.

Every year, when the lake rose, the place was flooded, with enormous damage to the property of the inhabitants; and sometimes an inundation of greater depth than usual threatened as complete a destruction as Cortes and the Tlascalans had made.

At the best of times, the site was a salt-swamp, an ugly place to build upon.