Although of different linguistic stocks and religion, the homes of the pueblo Indians are very similar. Almost without exception the pueblos built on mesa summits are of sandstone or other rock, plastered with adobe mud brought up from the water-courses of the valley. Those pueblos that are located in the valley, on the other hand, are generally built of adobe. No one can doubt that the Indians chose these elevated mesa sites for purposes of protection. With but one or two almost inaccessible trails reaching the heights, and these easily defendable, their homes were their fortresses. Their fields, gardens, and hunting-grounds were in the valleys or far-away mountains, whither they could go in times of peace; but, when attacked by foes, they fled up the trails, established elaborate methods of defence, and remained in their fortress-homes until the danger was past. The very construction of the houses reveals this. In none of the older houses is there any doorway into the lowest story. A solid wall faces the visitor, with perhaps a small window-hole. A rude ladder outside and a similar one inside afford the only means of entrance. One climbs up the ladder outside, drops through a hole in the roof, and descends the ladder inside. When attacked, the outer ladder could be drawn up, and thus, if we remember the crude weapons of the aborigines when discovered by the white man, it is evident that the inhabitants would remain in comparative security. Of late years doors and windows have been introduced into many of the ancient houses.