Lieut. Ives, who visited them in 1858, has left quite a full description of them. He states that “each pueblo is built around a rectangular court, in which, we suppose, are the springs that furnished the supply to the reservoirs. The exterior walls, which are of stone, have no openings, and would have to be scaled or battered down before access could be gained to the interior. The successive stories are set back, one behind the other. The lower rooms are reached through trap-doors from the first landing. The houses are three rooms deep, and open upon the interior court.”16 He was much pleased with the manner in which they had terraced off the bluff of the mesas into little garden patches, irrigating them from the large reservoirs from the top. There is one feature common to all the Pueblo tribes which is necessary to refer to here, from its connection with the ruined structures further north. In all of the inhabited pueblos there is a structure known as an Estafa, some pueblos having several. They are usually circular, but occasionally (as at Jemez) rectangular. They are generally subterranean, or mostly so. They are great institutions among the Pueblos. “In these subterranean temples the old men met in secret council, or assembled in worship of their gods. Here are held dances, festivities, and social intercourse.” Another common feature, represented in this cut, is the watch-tower. It is either round, as in this case, or rectangular. It may be interesting to recall in this connection the signal mounds of the Mound Builders. They were not always in the immediate vicinity of other ruins. Neither can we state that there was a system in their arrangement, one answering to another at a distance, and yet it was noticed where the rains were numerous that several were in view from one point.17 In dimensions these towers range from ten to fifteen feet in diameter, and from five to fifteen feet in height, while the walls are from one to two feet thick. They are in many cases connected with structures rectangular in form. Watch Tower.