To the north of the Mexican valley ancient ruins arrest the gaze of the traveller, onward even to California. On the Rio Colorado and its tributaries, ruins of great extent, surveyed by recent exploring parties, are described as built with large stones, nicely wrought, and accurately squared. But nothing in their style of architecture suggests a common origin with the ruins of Mexico or Central America. They are large and plain structures, with massive walls, evidently built for defence, and with no traces of the ornamentation which abounds on the ruins of Yucatan. The Moqui Indians, the supposed remnant of the ancient builders, still construct their dwellings of stone with considerable art and skill. They are a gentle and intelligent race, small of stature, with fine black hair; and differ essentially from the Indians of the North-west. Their villages are included in one common stone structure, generally of a quadrangular form, with solid, unpierced walls externally, and accessible only by means of a ladder. These hive-like colonies are usually placed, for further defence, on the summits of the lofty plateaus, which in the region of New Mexico are detached by the broad cañons with which that remarkable region is intersected. By such means this ingenious people seek protection from the wild tribes with which they are surrounded. Thus permanently settled, while exposed to the assaults of marauders, the Moquis cultivate the soil, raise corn, beans, cotton, and more recently vegetables derived from intercourse with the Mexicans. They have also their flocks of sheep and goats; and weave their dyed wools into a variety of substantial and handsome dresses. But only a small remnant now survives, occupying seven villages on the range of the Rio del Norte.[98] Throughout New California ruined structures of stone, and sometimes of clay abound. The _Casas grandes_, as they are called, appear to have been defensive structures like the Moqui villages. Captain Johnston describes one, called the Casa de Montezuma, on the river Gila, which measured fifty feet by forty, and had been form storeys high. It is indeed worthy of note that while we find throughout the continent, from the Rocky Mountains to the Atlantic, scarcely a vestige of ante-Columbian stone architecture: traces of it increase upon us with every new exploration of the country that lies between the Rocky Mountains and the Pacific, and merges towards the south into the seats of ancient native civilisation and matured architectural skill.