The rooms of the community houses were scarcely larger than the cave rooms already described; almost none of the surviving ground-floor rooms are more than 10 by 12 feet, and the typical room measures perhaps 7 by 10 feet. These chambers were quite dark and unventilated, since there were almost no windows or even connecting doorways between rooms; almost every room of the ground floor was entered by a ladder through an opening in its ceiling. It is conjectured that these first-floor cells were designed in this fashion to serve as storage places for foodstuffs, more secure from rodents by reason of having only one opening in the roof. Moreover, the lower-floor walls were a stronger foundation for the upper floors when built without door or window openings. Finally, this design provided maximum security for defense against human marauders. It has been mentioned that a composite type of building, combining cave rooms and masonry walls, is common in the area. This sort of construction was responsible for the many rows of small holes still to be seen in the cliffs, evenly spaced some 2 feet apart above the cave doorways. These holes were cut and used as sockets to support the ends of roof beams extending forward from the cliff and providing ceilings for the masonry rooms which once stood there. These evenly spaced holes, which you first see along many of the canyon walls, give mute evidence of the early aboriginal occupation of this area. Many of these talus dwellings reached a height of 3 stories and pushed out from the cliff 3 and 4 rooms deep, so that the cave rooms which were occupied first became relegated to storage space in the dark rear interiors. To conclude this general summation of ruin types, some description should be made of kivas. Kivas were, and are, the ceremonial chambers of the Pueblo people; as such, they are universally present in the Pajarito communities and their design makes them identifiable even in the ruined state. The local kivas were always round and were dug almost full-depth into the ground, except for certain examples which were excavated into the relatively soft bedrock of cliff or mesa-top. The circular depressions still to be found in the plazas of the great communal houses are the remains of kivas with their roofs collapsed and with the wind-borne debris of centuries accumulated in the hollows. A more complete discussion of kivas and their functions will be found on page 12. [Illustration: _Entrances to cave rooms._] _Principal Ruins of the National Monument_ Bandelier National Monument is divided into two parcels of land: the Otowi section of about 9 square miles and the Frijoles section of nearly 33 square miles. Within these two areas are contained great concentrations of ruins, including several of the largest on the plateau. A number of the Bandelier ruins have been excavated, so there is quite a detailed knowledge of the culture which once flourished on the monument lands.