On the San Juan, about ten miles above the mouth of the Mancos, is a significant combination of cave-dwellings and towers. In this case, about half-way up the cliff, which is not more than forty feet high, excavations had been made in a soft bed of shale. They are now quite shallow, but were probably once deeper and walled up in front. Directly above these cave-openings, on the very brink of the cliffs, were the remains of two circular towers, in each case double-walled, and probably divided by cross-walls into partitions. The towers were probably their council chambers and places of worship. The caves, directly below, down a steep bank, were their fortresses, whither in times of danger they could flee. The little community, by means of ladders, could freely pass from their cave resorts to the towers and back. Ruins in the San Juan Cañon. The San Juan River does not seem to be as rich in ruins as some of its tributaries. Yet near the mouth of the Montezuma we came upon a ruin which shows considerable analogy to the pueblos. Mr. Jackson says upon the top of the bench (fifty feet high) overlooking the river are the ruins of a quadrangular structure of a peculiar design. It is arranged very nearly at right angles to the river. We see from the plan that we have the ruins of a larger building arranged around an open court—at least, Mr. Jackson could detect no trace of a wall in front. We must notice the seven apartments, arranged in the form of a semicircle, back of the court. Extreme massiveness is indicated throughout the whole structure. In the immediate vicinity of this ruin were found a number of little, cave-like dwellings. They were so small that doubts were raised as to whether they were suitable for human habitations, but the majority of them bore ample evidence in smoke-begrimed walls that such was their use. Twelve miles below the mouth of the Montezuma this group of ruins was discovered. These were situated in a cave that was almost exactly a hemisphere in shape. Where the curve of the roof met the curve from the bottom a little projecting bench had been utilized as a foundation for a row of houses. Cave-Town.